diff --git a/Dockerfile b/Dockerfile
index 128be18f..ed3db106 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 FROM ocaml/opam:debian-10-ocaml-4.12@sha256:80e2b0337fe1c44d2f95ac35589b0a2eed4c65d8f12c3e33c12262065106c0c1 AS build
-RUN sudo apt-get update && sudo apt-get install capnproto graphviz m4 pkg-config libsqlite3-dev libgmp-dev libssl-dev libffi-dev -y --no-install-recommends
+RUN sudo apt-get update && sudo apt-get install libev-dev capnproto graphviz m4 pkg-config libsqlite3-dev libgmp-dev libssl-dev libffi-dev -y --no-install-recommends
 RUN cd ~/opam-repository && git pull origin -q master && git reset --hard 1a8b75438a8a47be909af0e6c0768c25384697c6 && opam update
 COPY --chown=opam \
 	ocurrent/current.opam \
@@ -31,7 +31,7 @@ ADD --chown=opam . .
 RUN opam config exec -- dune build ./src/base_images.exe
 
 FROM debian:10
-RUN apt-get update && apt-get install curl git graphviz libsqlite3-dev ca-certificates netbase gnupg2 -y --no-install-recommends
+RUN apt-get update && apt-get install libev4 curl git graphviz libsqlite3-dev ca-certificates netbase gnupg2 -y --no-install-recommends
 RUN curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add -
 RUN echo 'deb [arch=amd64] https://download.docker.com/linux/debian buster stable' >> /etc/apt/sources.list
 RUN apt-get update && apt-get install docker-ce -y --no-install-recommends
diff --git a/README.md b/README.md
index 89ae862c..5833f569 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 This is an [OCurrent][] pipeline that builds Docker images for OCaml, for
-various combinations of Linux distribution, OCaml version and architecture.
+various combinations of Linux distribution, Windows version, OCaml version
+and architecture.
 
 The resulting images can be run as e.g.
 
diff --git a/base-images.opam b/base-images.opam
index 7b046184..abcdfaa4 100644
--- a/base-images.opam
+++ b/base-images.opam
@@ -8,6 +8,7 @@ bug-reports: "https://github.com/ocurrent/docker-base-images/issues"
 depends: [
   "dune" {>= "2.5"}
   "ocaml" {>= "4.12"}
+  "conf-libev" {os != "win32"}
   "prometheus-app" {>= "1.0"}
   "ppx_sexp_conv"
   "ppx_deriving_yojson"
diff --git a/builds.expected b/builds.expected
index ee4c32fc..c4ec07c8 100644
--- a/builds.expected
+++ b/builds.expected
@@ -7482,3 +7482,1221 @@ ocurrent/opam-staging:ubuntu-21.04-ocaml-4.13-ppc64le, ocurrent/opam-staging:ubu
 	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
 ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-ppc64le, ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-arm64, ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-amd64 -> ocaml/opam:ubuntu-21.04-ocaml-4.14
 ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-ppc64le, ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-arm64, ocurrent/opam-staging:ubuntu-21.04-ocaml-4.14-amd64 -> ocaml/opam:ubuntu-ocaml-4.14
+windows-mingw
+windows-mingw-1809/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:1809 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:1809
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-mingw-1909/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:1909 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:1909
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-mingw-2004/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:2004 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:2004
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-mingw-20H2/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:20H2 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:20H2
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-core,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.12.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.12-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-ocaml-4.12
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.11.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.11-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.11-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.11-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-ocaml-4.11
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.10.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.10-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.10-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.10-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-ocaml-4.10
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.09.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.09-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.09-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.09-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-ocaml-4.09
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.08.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.08-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.08-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.08-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-ocaml-4.08
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.07.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.07-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.07-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.07-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-ocaml-4.07
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.06.1+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.06-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.06-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.06-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-ocaml-4.06
+4.05.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.05 --packages=ocaml-variants.4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.05.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.05 --packages=ocaml-variants.4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.05.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.05 --packages=ocaml-variants.4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.05.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.05 --packages=ocaml-variants.4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.05.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.05-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.05-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.05-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-ocaml-4.05
+4.04.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.04 --packages=ocaml-variants.4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.04.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.04 --packages=ocaml-variants.4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.04.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.04 --packages=ocaml-variants.4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.04.2/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.04 --packages=ocaml-variants.4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.04.2+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.04-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.04-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.04-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-ocaml-4.04
+4.03.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.03 --packages=ocaml-variants.4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.03.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.03 --packages=ocaml-variants.4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.03.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.03 --packages=ocaml-variants.4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.03.0/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.03 --packages=ocaml-variants.4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.03.0+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.03-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.03-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.03-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-ocaml-4.03
+4.02.3/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.02 --packages=ocaml-variants.4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.02.3/amd64
+	FROM ocurrent/opam-staging:windows-mingw-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.02 --packages=ocaml-variants.4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.02.3/amd64
+	FROM ocurrent/opam-staging:windows-mingw-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.02 --packages=ocaml-variants.4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.02.3/amd64
+	FROM ocurrent/opam-staging:windows-mingw-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --no-opam -- opam switch create 4.02 --packages=ocaml-variants.4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam pin add -k version ocaml-variants 4.02.3+mingw64
+	RUN ocaml-env exec --64 -- opam install -y depext depext-cygwinports
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.02-amd64, ocurrent/opam-staging:windows-mingw-1909-ocaml-4.02-amd64, ocurrent/opam-staging:windows-mingw-2004-ocaml-4.02-amd64, ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-1809-opam-amd64 -> ocaml/opam:windows-mingw-1809-opam
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.03
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.03
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.04
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.04
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.05
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.05
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.06
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.06
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.07
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.07
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.08
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.08
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.09
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.09
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.10
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.10
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.11
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.11
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-1809
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-1809-ocaml-4.12
+ocurrent/opam-staging:windows-mingw-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-ltsc2019-ocaml-4.12
+ocurrent/opam-staging:windows-mingw-1909-opam-amd64 -> ocaml/opam:windows-mingw-1909-opam
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.03
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.04
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.05
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.06
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.07
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.08
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.09
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.10
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.11
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-1909
+ocurrent/opam-staging:windows-mingw-1909-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-1909-ocaml-4.12
+ocurrent/opam-staging:windows-mingw-2004-opam-amd64 -> ocaml/opam:windows-mingw-2004-opam
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.03
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.04
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.05
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.06
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.07
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.08
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.09
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.10
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.11
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-2004
+ocurrent/opam-staging:windows-mingw-2004-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-2004-ocaml-4.12
+ocurrent/opam-staging:windows-mingw-20H2-opam-amd64 -> ocaml/opam:windows-mingw-20H2-opam
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.02-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.02
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.03-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.03
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.04-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.04
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.05-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.05
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.06-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.06
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.07-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.07
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.08-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.08
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.09-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.09
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.10-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.10
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.11-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.11
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-20H2
+ocurrent/opam-staging:windows-mingw-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-mingw-20H2-ocaml-4.12
+windows-msvc
+windows-msvc-1809/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:1809 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:1809
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ADD [ "https://raw.githubusercontent.com/MisterDA/Windows-OCaml-Docker/images/Install.cmd", "C:\\TEMP\\" ]
+	ADD [ "https://aka.ms/vscollect.exe", "C:\\TEMP\\collect.exe" ]
+	ADD [ "https://aka.ms/vs/16/release/channel", "C:\\TEMP\\VisualStudio.chman" ]
+	ADD [ "https://aka.ms/vs/16/release/vs_buildtools.exe", "C:\\TEMP\\vs_buildtools.exe" ]
+	RUN C:\TEMP\Install.cmd C:\TEMP\vs_buildtools.exe --quiet --wait --norestart --nocache `
+	        --installPath C:\BuildTools --channelUri C:\TEMP\VisualStudio.chman `
+	        --installChannelUri C:\TEMP\VisualStudio.chman `
+	        --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+	        --add Microsoft.VisualStudio.Component.Windows10SDK.18362
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-msvc-1909/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:1909 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:1909
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ADD [ "https://raw.githubusercontent.com/MisterDA/Windows-OCaml-Docker/images/Install.cmd", "C:\\TEMP\\" ]
+	ADD [ "https://aka.ms/vscollect.exe", "C:\\TEMP\\collect.exe" ]
+	ADD [ "https://aka.ms/vs/16/release/channel", "C:\\TEMP\\VisualStudio.chman" ]
+	ADD [ "https://aka.ms/vs/16/release/vs_buildtools.exe", "C:\\TEMP\\vs_buildtools.exe" ]
+	RUN C:\TEMP\Install.cmd C:\TEMP\vs_buildtools.exe --quiet --wait --norestart --nocache `
+	        --installPath C:\BuildTools --channelUri C:\TEMP\VisualStudio.chman `
+	        --installChannelUri C:\TEMP\VisualStudio.chman `
+	        --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+	        --add Microsoft.VisualStudio.Component.Windows10SDK.18362
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-msvc-2004/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:2004 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:2004
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ADD [ "https://raw.githubusercontent.com/MisterDA/Windows-OCaml-Docker/images/Install.cmd", "C:\\TEMP\\" ]
+	ADD [ "https://aka.ms/vscollect.exe", "C:\\TEMP\\collect.exe" ]
+	ADD [ "https://aka.ms/vs/16/release/channel", "C:\\TEMP\\VisualStudio.chman" ]
+	ADD [ "https://aka.ms/vs/16/release/vs_buildtools.exe", "C:\\TEMP\\vs_buildtools.exe" ]
+	RUN C:\TEMP\Install.cmd C:\TEMP\vs_buildtools.exe --quiet --wait --norestart --nocache `
+	        --installPath C:\BuildTools --channelUri C:\TEMP\VisualStudio.chman `
+	        --installChannelUri C:\TEMP\VisualStudio.chman `
+	        --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+	        --add Microsoft.VisualStudio.Component.Windows10SDK.18362
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+windows-msvc-20H2/amd64
+	# escape=`
+	FROM mcr.microsoft.com/windows:20H2 as winget-builder
+	USER ContainerAdministrator
+	ADD [ "https://github.com/microsoft/winget-cli/releases/latest/download/Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.msixbundle", "C:\\TEMP\\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip" ]
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe.zip -DestinationPath C:\TEMP\winget-cli -Force"
+	RUN ren C:\TEMP\winget-cli\AppInstaller_x64.msix AppInstaller_x64.zip
+	RUN powershell -Command "Expand-Archive -LiteralPath C:\TEMP\winget-cli\AppInstaller_x64.zip -DestinationPath C:\TEMP\winget-cli\ -Force"
+	RUN mkdir "C:\Program Files\winget-cli" && `
+	  move "C:\TEMP\winget-cli\\AppInstallerCLI.exe" "C:\Program Files\winget-cli\winget.exe" && `
+	  move "C:\TEMP\winget-cli\\resources.pri" "C:\Program Files\winget-cli\"
+	# escape=`
+	# Autogenerated by OCaml-Dockerfile scripts
+	FROM mcr.microsoft.com/windows:20H2
+	LABEL distro_style="windows"
+	USER ContainerAdministrator
+	ADD [ "https://aka.ms/vs/16/release/vc_redist.x64.exe", "C:\\TEMP\\" ]
+	RUN C:\TEMP\vc_redist.x64.exe /install /passive /norestart /log C:\TEMP\vc_redist.log
+	ADD [ "https://raw.githubusercontent.com/MisterDA/Windows-OCaml-Docker/images/Install.cmd", "C:\\TEMP\\" ]
+	ADD [ "https://aka.ms/vscollect.exe", "C:\\TEMP\\collect.exe" ]
+	ADD [ "https://aka.ms/vs/16/release/channel", "C:\\TEMP\\VisualStudio.chman" ]
+	ADD [ "https://aka.ms/vs/16/release/vs_buildtools.exe", "C:\\TEMP\\vs_buildtools.exe" ]
+	RUN C:\TEMP\Install.cmd C:\TEMP\vs_buildtools.exe --quiet --wait --norestart --nocache `
+	        --installPath C:\BuildTools --channelUri C:\TEMP\VisualStudio.chman `
+	        --installChannelUri C:\TEMP\VisualStudio.chman `
+	        --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 `
+	        --add Microsoft.VisualStudio.Component.Windows10SDK.18362
+	ENV CYGWIN="winsymlinks:native"
+	ADD [ "https://www.cygwin.com/setup-x86_64.exe", "C:\\cygwin-setup-x86_64.exe" ]
+	RUN mkdir C:\cygwin64\lib\cygsympathy && mkdir C:\cygwin64\etc\postinstall
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.cmd", "C:\\cygwin64\\lib\\cygsympathy\\" ]
+	ADD [ "https://raw.githubusercontent.com/metastack/cygsympathy/master/cygsympathy.sh", "C:\\cygwin64\\lib\\cygsympathy\\cygsympathy" ]
+	RUN mklink C:\cygwin64\etc\postinstall\zp_zcygsympathy.sh C:\cygwin64\lib\cygsympathy\cygsympathy
+	RUN C:\cygwin-setup-x86_64.exe --quiet-mode --no-shortcuts --no-startmenu --no-desktop --only-site --local-package-dir C:\TEMP\cache --root C:\cygwin64 --site http://mirrors.kernel.org/sourceware/cygwin/ --packages curl,diffutils,git,m4,make,mingw64-x86_64-binutils=2.35.2-1,mingw64-x86_64-gcc-g++,patch,rsync,unzip,vim
+	ADD [ "https://github.com/metastack/msvs-tools/archive/0.4.1.tar.gz", "C:\\TEMP\\msvs-tools.tar.gz" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/msvs-tools.tar.gz && cp msvs-tools-0.4.1/msvs-detect msvs-tools-0.4.1/msvs-promote-path /bin"
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\cygwin64\bin;%c"
+	RUN awk -i inplace "/(^#)|(^$)/{print;next}{$4=""noacl,""$4; print}" C:\cygwin64\etc\fstab
+	WORKDIR C:\cygwin64\home\opam
+	ADD [ "https://github.com/fdopen/opam-repository-mingw/releases/download/0.0.0.2/opam64.tar.xz", "C:\\TEMP\\" ]
+	RUN C:\cygwin64\bin\bash.exe --login -c "cd /tmp && tar -xf /cygdrive/c/TEMP/opam64.tar.xz && ./opam64/install.sh --prefix=/usr && rm -rf opam64 opam64.tar.xz"
+	COPY --from=winget-builder [ "C:\\Program Files\\winget-cli", "C:\\Program Files\\winget-cli" ]
+	RUN for /f "tokens=1,2,*" %a in ('reg query "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path ^| findstr /r "^[^H]"') do `
+	        reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment" /V Path /t REG_EXPAND_SZ /f /d "C:\Program Files\winget-cli;%c"
+	RUN powershell -Command "winget settings ; `
+	        $path=""""${Env:LocalAppData}\Microsoft\WinGet\Settings\settings.json"""" ; `
+	        $json=(Get-Content -Encoding ascii $path | Select -SkipLast 1) -Join """"`n"""" ; `
+	        $json=($json, '    """"telemetry"""": { """"disable"""": true },', """"}"""") -Join """"`n"""" ; `
+	        $json | Set-Content -Encoding ascii -NoNewLine $path ; `
+	        winget settings"
+	RUN winget install git
+	ENV HOME="C:\cygwin64\home\opam"
+	RUN C:\cygwin64\bin\bash.exe --login -c "git config --global user.email 'docker@example.com' && git config --global user.name 'Docker' && git config --system core.longpaths true"
+	RUN powershell -Command "Remove-Item 'C:\TEMP' -Recurse"
+	COPY [ ".", "C:\\cygwin64\\home\\opam\\opam-repository" ]
+	ENV OPAMROOT="C:\opam\.opam"
+	RUN opam init -k local -a "C:\cygwin64\home\opam\opam-repository" --bare --disable-sandboxing
+	RUN C:\cygwin64\bin\bash.exe --login -c "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+	COPY [ "Dockerfile", "/Dockerfile.opam" ]
+4.12.0/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.12 --packages=ocaml-variants.4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.12.0+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.12-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-ocaml-4.12
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.11.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.11 --packages=ocaml-variants.4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.11.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.11-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.11-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.11-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-ocaml-4.11
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.10.2/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.10 --packages=ocaml-variants.4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.10.2+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.10-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.10-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.10-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-ocaml-4.10
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.09.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.09 --packages=ocaml-variants.4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.09.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.09-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.09-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.09-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-ocaml-4.09
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.08.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.08 --packages=ocaml-variants.4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.08.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.08-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.08-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.08-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-ocaml-4.08
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.07.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.07 --packages=ocaml-variants.4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.07.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.07-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.07-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.07-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-ocaml-4.07
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1809-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-1909-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-2004-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+4.06.1/amd64
+	FROM ocurrent/opam-staging:windows-msvc-20H2-opam-amd64
+	ENV OPAMYES="1" OPAMCONFIRMLEVEL="unsafe-yes" OPAMERRLOGLEN="0" OPAMPRECISETRACKING="1"
+	RUN ocaml-env exec --64 --ms=vs2019 --no-opam -- opam switch create 4.06 --packages=ocaml-variants.4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam pin add -k version ocaml-variants 4.06.1+msvc64
+	RUN ocaml-env exec --64 --ms=vs2019 -- opam install -y depext
+	ENTRYPOINT [ "ocaml-env", "exec", "--64", "--ms=vs2019", "--" ]
+	CMD [ "cmd.exe" ]
+	COPY [ "Dockerfile", "/Dockerfile.ocaml" ]
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.06-amd64, ocurrent/opam-staging:windows-msvc-1909-ocaml-4.06-amd64, ocurrent/opam-staging:windows-msvc-2004-ocaml-4.06-amd64, ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-1809-opam-amd64 -> ocaml/opam:windows-msvc-1809-opam
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.07
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.07
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.08
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.08
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.09
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.09
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.10
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.10
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.11
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.11
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-1809
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-1809-ocaml-4.12
+ocurrent/opam-staging:windows-msvc-1809-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-ltsc2019-ocaml-4.12
+ocurrent/opam-staging:windows-msvc-1909-opam-amd64 -> ocaml/opam:windows-msvc-1909-opam
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.07
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.08
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.09
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.10
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.11
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-1909
+ocurrent/opam-staging:windows-msvc-1909-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-1909-ocaml-4.12
+ocurrent/opam-staging:windows-msvc-2004-opam-amd64 -> ocaml/opam:windows-msvc-2004-opam
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.07
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.08
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.09
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.10
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.11
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-2004
+ocurrent/opam-staging:windows-msvc-2004-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-2004-ocaml-4.12
+ocurrent/opam-staging:windows-msvc-20H2-opam-amd64 -> ocaml/opam:windows-msvc-20H2-opam
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.06-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.06
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.07-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.07
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.08-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.08
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.09-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.09
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.10-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.10
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.11-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.11
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-20H2
+ocurrent/opam-staging:windows-msvc-20H2-ocaml-4.12-amd64 -> ocaml/opam:windows-msvc-20H2-ocaml-4.12
diff --git a/dune-project b/dune-project
index c78616b7..13cc787d 100644
--- a/dune-project
+++ b/dune-project
@@ -10,6 +10,7 @@
  (synopsis "Generate Docker base images for OCaml and opam using ocurrent")
  (depends
   (ocaml (>= 4.12))
+  (conf-libev (<> :os "win32"))
   (prometheus-app (>= 1.0))
   ppx_sexp_conv
   ppx_deriving_yojson
diff --git a/src/conf.ml b/src/conf.ml
index 47100d7e..b09bbc59 100644
--- a/src/conf.ml
+++ b/src/conf.ml
@@ -3,7 +3,10 @@ let staging_repo = "ocurrent/opam-staging"
 
 let public_repo = "ocaml/opam"
 
-let password_path = "/run/secrets/ocurrent-hub"
+let password_path =
+  let open Fpath in
+  let root = v (if Sys.win32 then "C:\\ProgramData\\Docker" else "/run") in
+  root / "secrets" / "ocurrent-hub" |> to_string
 
 module Capnp = struct
   (* Cap'n Proto RPC is enabled by passing --capnp-public-address. These values are hard-coded
@@ -36,8 +39,11 @@ let pool_name os_family arch =
 
 let switches ~arch ~distro =
   let is_tier1 = List.mem distro (Dockerfile_distro.active_tier1_distros arch) in
+  (* opam-repository-mingw doesn't package the development version of
+     the compiler. *)
+  let with_dev = match distro with `Windows _ -> false | _ -> true in
   let main_switches =
-    Ocaml_version.Releases.recent_with_dev
+    Ocaml_version.Releases.(if with_dev then recent_with_dev else recent)
     |> List.filter (fun ov -> Dockerfile_distro.distro_supported_on arch ov distro)
   in
   if is_tier1 then (
@@ -47,7 +53,10 @@ let switches ~arch ~distro =
   )
 
 (* We can't get the active distros directly, but assume x86_64 is a superset of everything else. *)
-let distros = Dockerfile_distro.(active_distros `X86_64 |> List.filter (fun d -> os_family_of_distro d = `Linux))
+let distros = Dockerfile_distro.(active_distros `X86_64 |> List.filter (fun d ->
+  match os_family_of_distro d with
+  | `Linux | `Windows -> true
+  | _ -> false))
 
 let arches_for ~distro = Dockerfile_distro.distro_arches Ocaml_version.Releases.latest distro
 
diff --git a/src/dump.ml b/src/dump.ml
index 2cadfd8f..be04600c 100644
--- a/src/dump.ml
+++ b/src/dump.ml
@@ -95,6 +95,7 @@ let run () =
   let repos =
     Fake.Current.Primitive.const { Git_repositories.
       opam_repository_master = Current_git.Commit_id.v ~repo:"opam_repository" ~gref:"master" ~hash:"master";
+      opam_repository_mingw_opam2 = Current_git.Commit_id.v ~repo:"opam_repository_mingw_opam2" ~gref:"master" ~hash:"master";
       opam_2_0 = Current_git.Commit_id.v ~repo:"opam" ~gref:"2.0" ~hash:"2.0";
       opam_2_1 = Current_git.Commit_id.v ~repo:"opam" ~gref:"2.1" ~hash:"2.1";
     } in
diff --git a/src/git_repositories.ml b/src/git_repositories.ml
index 86a4fbfe..6a2b0545 100644
--- a/src/git_repositories.ml
+++ b/src/git_repositories.ml
@@ -16,13 +16,15 @@ module Repositories = struct
 
     type t = {
       opam_repository_master : repo;
+      opam_repository_mingw_opam2 : repo;
       opam_2_0 : repo;
       opam_2_1 : repo;
     }
 
-    let digest {opam_repository_master; opam_2_0; opam_2_1} =
+    let digest {opam_repository_master; opam_repository_mingw_opam2; opam_2_0; opam_2_1} =
       let json = `Assoc [
         "opam-repository__master", `String opam_repository_master;
+        "opam-repository-mingw__opam2", `String opam_repository_mingw_opam2;
         "opam__2.0", `String opam_2_0;
         "opam__2.1", `String opam_2_1;
       ] in
@@ -34,6 +36,7 @@ module Repositories = struct
 
     type t = {
       opam_repository_master : hash;
+      opam_repository_mingw_opam2 : hash;
       opam_2_0 : hash;
       opam_2_1 : hash;
     } [@@deriving yojson]
@@ -52,12 +55,13 @@ module Repositories = struct
     Current.Process.check_output ~cwd ~cancellable:true ~job ("", [|"git"; "rev-parse"; "HEAD"|]) >>!= fun hash ->
     Lwt.return (Ok (String.trim hash))
 
-  let build No_context job {Key.opam_repository_master; opam_2_0; opam_2_1} =
+  let build No_context job {Key.opam_repository_master; opam_repository_mingw_opam2; opam_2_0; opam_2_1} =
     Current.Job.start job ~level:Current.Level.Mostly_harmless >>= fun () ->
     get_commit_hash ~job ~repo:opam_repository_master ~branch:"master" >>!= fun opam_repository_master ->
+    get_commit_hash ~job ~repo:opam_repository_mingw_opam2 ~branch:"opam2" >>!= fun opam_repository_mingw_opam2 ->
     get_commit_hash ~job ~repo:opam_2_0 ~branch:"2.0" >>!= fun opam_2_0 ->
     get_commit_hash ~job ~repo:opam_2_1 ~branch:"2.1" >>!= fun opam_2_1 ->
-    Lwt.return (Ok {Value.opam_repository_master; opam_2_0; opam_2_1})
+    Lwt.return (Ok {Value.opam_repository_master; opam_repository_mingw_opam2; opam_2_0; opam_2_1})
 
   let pp f _ = Fmt.string f "Git repositories"
 
@@ -68,6 +72,7 @@ module Cache = Current_cache.Make(Repositories)
 
 type t = {
   opam_repository_master : Current_git.Commit_id.t;
+  opam_repository_mingw_opam2 : Current_git.Commit_id.t;
   opam_2_0 : Current_git.Commit_id.t;
   opam_2_1 : Current_git.Commit_id.t;
 }
@@ -76,10 +81,11 @@ let get ~schedule =
   let key = {
     Repositories.Key.
     opam_repository_master = "git://github.com/ocaml/opam-repository";
+    opam_repository_mingw_opam2 = "git://github.com/fdopen/opam-repository-mingw";
     opam_2_0 = "git://github.com/ocaml/opam";
     opam_2_1 = "git://github.com/ocaml/opam";
   } in
-  let+ {Repositories.Value.opam_repository_master; opam_2_0; opam_2_1} =
+  let+ {Repositories.Value.opam_repository_master; opam_repository_mingw_opam2; opam_2_0; opam_2_1} =
     Current.component "Git-repositories" |>
     let> key = Current.return key in
     Cache.get ~schedule Repositories.No_context key
@@ -87,6 +93,8 @@ let get ~schedule =
   {
     opam_repository_master =
       Current_git.Commit_id.v ~repo:key.opam_repository_master ~gref:"master" ~hash:opam_repository_master;
+    opam_repository_mingw_opam2 =
+      Current_git.Commit_id.v ~repo:key.opam_repository_mingw_opam2 ~gref:"opam2" ~hash:opam_repository_mingw_opam2;
     opam_2_0 =
       Current_git.Commit_id.v ~repo:key.opam_2_0 ~gref:"2.0" ~hash:opam_2_0;
     opam_2_1 =
diff --git a/src/git_repositories.mli b/src/git_repositories.mli
index 8d3de91c..95be8804 100644
--- a/src/git_repositories.mli
+++ b/src/git_repositories.mli
@@ -1,5 +1,6 @@
 type t = {
   opam_repository_master : Current_git.Commit_id.t;
+  opam_repository_mingw_opam2 : Current_git.Commit_id.t;
   opam_2_0 : Current_git.Commit_id.t;
   opam_2_1 : Current_git.Commit_id.t;
 }
diff --git a/src/pipeline.ml b/src/pipeline.ml
index 982770d9..562f6f26 100644
--- a/src/pipeline.ml
+++ b/src/pipeline.ml
@@ -13,27 +13,27 @@ let aliases_of =
 
 let master_distro = Dockerfile_distro.(resolve_alias master_distro)
 
-let maybe_add_beta switch =
-  let open Dockerfile in
+type 'a run = ('a, unit, string, Dockerfile.t) format4 -> 'a
+
+let maybe_add_beta (run : 'a run) switch =
   if Ocaml_version.Releases.is_dev switch then
     run "opam repo add beta git://github.com/ocaml/ocaml-beta-repository --set-default"
   else
-    empty
+    Dockerfile.empty
 
-let maybe_add_multicore switch =
-  let open Dockerfile in
+let maybe_add_multicore (run : 'a run) switch =
   if Ocaml_version.Configure_options.is_multicore switch then
     run "opam repo add multicore git://github.com/ocaml-multicore/multicore-opam --set-default"
   else
-    empty
+    Dockerfile.empty
 
-let maybe_install_secondary_compiler ~switch =
+let maybe_install_secondary_compiler (run : 'a run) os_family switch =
   let dune_min_native_support = Ocaml_version.Releases.v4_08 in
-  let open Dockerfile in
-  if Ocaml_version.compare switch dune_min_native_support < 0 then
+  (* opam-repository-mingw doesn't package ocaml-secondary-compiler. *)
+  if Ocaml_version.compare switch dune_min_native_support < 0 && os_family <> `Windows then
     run "opam install -y ocaml-secondary-compiler"
   else
-    empty
+    Dockerfile.empty
 
 let install_package_archive opam_image =
   let open Dockerfile in
@@ -44,28 +44,50 @@ let install_package_archive opam_image =
   copy ~chown:"0:0" ~from:"archive" ~src:["/home/opam/opam-repository/cache"] ~dst:"/cache" ()
 
 (* Generate a Dockerfile to install OCaml compiler [switch] in [opam_image]. *)
-let install_compiler_df ~os_family ~arch ~switch opam_image =
-  let switch_name = Ocaml_version.to_string (Ocaml_version.with_just_major_and_minor switch) in
-  let (package_name, package_version) = Ocaml_version.Opam.V2.package switch in
-  let additional_packages = Ocaml_version.Opam.V2.additional_packages switch in
-  let personality = Dockerfile_distro.personality os_family arch in
+let install_compiler_df ~os_family ~arch ~switch ?windows_port opam_image =
+  let switch_name = Ocaml_version.(with_just_major_and_minor switch |> to_string) in
+  let (package_name, package_version) =
+    match windows_port with
+    | None -> Ocaml_version.Opam.V2.package switch
+    | Some port -> Dockerfile_windows.ocaml_for_windows_package_exn ~switch ~arch ~port
+  in
   let open Dockerfile in
-  let shell = Option.fold ~none:empty ~some:(fun pers -> shell [pers; "/bin/sh"; "-c"]) personality in
+  let personality = Dockerfile_distro.personality os_family arch in
+  let run, run_no_opam, depext, opam_exec =
+    let open Dockerfile_windows in
+    let bitness = if Ocaml_version.arch_is_32bit arch then "--32" else "--64" in
+    match windows_port with
+    | None ->
+      (fun fmt -> run fmt), (fun fmt -> run fmt), "opam-depext", ["opam"; "exec"; "--"]
+    | Some `Msvc ->
+      (fun fmt -> run_ocaml_env [bitness; "--ms=vs2019"] fmt),
+      (fun fmt -> run_ocaml_env [bitness; "--ms=vs2019"; "--no-opam"] fmt),
+       "depext", ["ocaml-env"; "exec"; bitness; "--ms=vs2019"; "--"]
+    | Some `Mingw ->
+      (fun fmt -> run_ocaml_env [bitness] fmt),
+      (fun fmt -> run_ocaml_env [bitness; "--no-opam"] fmt),
+      "depext depext-cygwinports", ["ocaml-env"; "exec"; bitness; "--"]
+  in
+  let shell = maybe (fun pers -> shell [pers; "/bin/sh"; "-c"]) personality in
+  let packages =
+    let additional_packages = Ocaml_version.Opam.V2.additional_packages switch in
+    String.concat "," (Printf.sprintf "%s.%s" package_name package_version :: additional_packages)
+  in
   from opam_image @@
   shell @@
-  maybe_add_beta switch @@
-  maybe_add_multicore switch @@
+  maybe_add_beta run switch @@
+  maybe_add_multicore run switch @@
   env ["OPAMYES", "1";
        "OPAMCONFIRMLEVEL", "unsafe-yes";
        "OPAMERRLOGLEN", "0"; (* Show the whole log if it fails *)
        "OPAMPRECISETRACKING", "1"; (* Mitigate https://github.com/ocaml/opam/issues/3997 *)
       ] @@
-  run "opam switch create %s --packages=%s" switch_name (String.concat "," (Printf.sprintf "%s.%s" package_name package_version :: additional_packages)) @@
+  run_no_opam "opam switch create %s --packages=%s" switch_name packages @@
   run "opam pin add -k version %s %s" package_name package_version @@
-  run "opam install -y opam-depext" @@
-  maybe_install_secondary_compiler ~switch @@
-  entrypoint_exec (Option.to_list personality @ ["opam"; "exec"; "--"]) @@
-  cmd "bash" @@
+  run "opam install -y %s" depext @@
+  maybe_install_secondary_compiler run os_family switch @@
+  entrypoint_exec (Option.to_list personality @ opam_exec) @@
+  (match os_family with `Linux | `Cygwin -> cmd "bash" | `Windows -> cmd_exec ["cmd.exe"]) @@
   copy ~src:["Dockerfile"] ~dst:"/Dockerfile.ocaml" ()
 
 let or_die = function
@@ -78,11 +100,14 @@ module Make (OCurrent : S.OCURRENT) = struct
 
   (* Pipeline to build the opam base image and the compiler images for a particular architecture. *)
   module Arch = struct
+    (* 2020-04-29: On Windows, squashing images is still experimental (broken). *)
+    let squash os_family = os_family <> `Windows
+
     let install_opam ~arch ~ocluster ~distro ~repos ~push_target =
       let arch_name = Ocaml_version.string_of_arch arch in
-      let distro_tag = Dockerfile_distro.tag_of_distro distro in
+      let distro_tag, os_family = Dockerfile_distro.(tag_of_distro distro, os_family_of_distro distro) in
       Current.component "%s@,%s" distro_tag arch_name |>
-      let> {Git_repositories.opam_repository_master; opam_2_0; opam_2_1} = repos in
+      let> {Git_repositories.opam_repository_master; opam_repository_mingw_opam2; opam_2_0; opam_2_1} = repos in
       let dockerfile =
         let hash_opam_2_0 = Current_git.Commit_id.hash opam_2_0 in
         let hash_opam_2_1 = Current_git.Commit_id.hash opam_2_1 in
@@ -91,29 +116,42 @@ module Make (OCurrent : S.OCURRENT) = struct
           let open Dockerfile in
           string_of_t (
             opam @@
-            copy ~chown:"opam:opam" ~src:["."] ~dst:"/home/opam/opam-repository" () @@
-            run "opam-sandbox-disable" @@
-            run "opam init -k local -a /home/opam/opam-repository --bare" @@
-            run "rm -rf .opam/repo/default/.git" @@
+            begin match os_family with
+            | `Cygwin | `Linux ->
+              copy ~chown:"opam:opam" ~src:["."] ~dst:"/home/opam/opam-repository" () @@
+              run "opam-sandbox-disable" @@
+              run "opam init -k local -a /home/opam/opam-repository --bare" @@
+              run "rm -rf .opam/repo/default/.git"
+            | `Windows ->
+              let opam_repo = Dockerfile_windows.Cygwin.default.root ^ {|\home\opam\opam-repository|} in
+              let opam_root = {|C:\opam\.opam|} in
+              copy ~src:["."] ~dst:opam_repo () @@
+              env [("OPAMROOT", opam_root)] @@
+              run "opam init -k local -a \"%s\" --bare --disable-sandboxing" opam_repo @@
+              Dockerfile_windows.Cygwin.run_sh "rm -rf /cygdrive/c/opam/.opam/repo/default/.git"
+            end @@
             copy ~src:["Dockerfile"] ~dst:"/Dockerfile.opam" ()
           )
         )
       in
-      let options = { Cluster_api.Docker.Spec.defaults with squash = true; include_git = true } in
+      let options = { Cluster_api.Docker.Spec.defaults with
+                      squash = squash (Dockerfile_distro.os_family_of_distro distro);
+                      include_git = true } in
       let cache_hint = Printf.sprintf "opam-%s" distro_tag in
-      OCluster.Raw.build_and_push ocluster ~src:[opam_repository_master] dockerfile
+      let opam_repository = match os_family with `Windows -> opam_repository_mingw_opam2 | _ -> opam_repository_master in
+      OCluster.Raw.build_and_push ocluster ~src:[opam_repository] dockerfile
         ~cache_hint
         ~options
         ~push_target
-        ~pool:(Conf.pool_name (Dockerfile_distro.os_family_of_distro distro) arch)
+        ~pool:(Conf.pool_name os_family arch)
 
-    let install_compiler ~os_family ~arch ~ocluster ~switch ~push_target base =
+    let install_compiler ~os_family ~arch ~ocluster ~switch ~push_target ?windows_port base =
       let arch_name = Ocaml_version.string_of_arch arch in
       Current.component "%s/%s" (Ocaml_version.to_string switch) arch_name |>
       let> base = base in
-      let dockerfile = `Contents (install_compiler_df ~os_family ~arch ~switch base |> Dockerfile.string_of_t) in
+      let dockerfile = `Contents (install_compiler_df ~os_family ~arch ~switch ?windows_port base |> Dockerfile.string_of_t) in
       (* ([include_git] doesn't do anything here, but it saves rebuilding during the upgrade) *)
-      let options = { Cluster_api.Docker.Spec.defaults with squash = true; include_git = true } in
+      let options = { Cluster_api.Docker.Spec.defaults with squash = squash os_family; include_git = true } in
       let cache_hint = Printf.sprintf "%s-%s-%s" (Ocaml_version.to_string switch) arch_name base in
       OCluster.Raw.build_and_push ocluster ~src:[] dockerfile
         ~cache_hint
@@ -125,7 +163,7 @@ module Make (OCurrent : S.OCURRENT) = struct
       Current.component "archive" |>
       let> base = base in
       let dockerfile = `Contents (install_package_archive base |> Dockerfile.string_of_t) in
-      let options = { Cluster_api.Docker.Spec.defaults with squash = true; include_git = true } in
+      let options = { Cluster_api.Docker.Spec.defaults with squash = squash os_family; include_git = true } in
       let cache_hint = Printf.sprintf "archive-%s" base in
       OCluster.Raw.build_and_push ocluster ~src:[] dockerfile
         ~cache_hint
@@ -151,7 +189,8 @@ module Make (OCurrent : S.OCURRENT) = struct
           |> Cluster_api.Docker.Image_id.of_string
           |> or_die
         in
-        let repo_id = install_compiler ~os_family ~arch ~ocluster ~switch ~push_target opam_image in
+        let windows_port = match distro with  `Windows (port, _) -> Some port | _ -> None in
+        let repo_id = install_compiler ~os_family ~arch ~ocluster ~switch ~push_target ?windows_port opam_image in
         (switch, repo_id)
       in
       (* Build the archive image for the debian 10 / x86_64 image only *)
@@ -181,58 +220,133 @@ module Make (OCurrent : S.OCURRENT) = struct
     let> v = t in
     Current.Primitive.const v
 
-  (* The main pipeline. Builds images for all supported distribution, compiler version and architecture combinations. *)
-  let v ~ocluster repos =
-    Current.all (
-      Conf.distros |> List.map @@ fun distro ->
-      let distro_label = Dockerfile_distro.tag_of_distro distro in
-      let repos = label distro_label repos in
-      Current.collapse ~key:"distro" ~value:distro_label ~input:repos @@
-      let opam_images, ocaml_images, archive_image =
-        let arch_results =
-          let arches = Conf.arches_for ~distro in
-          List.map (Arch.pipeline ~ocluster ~repos ~distro) arches in
-        List.fold_left (fun (aa,ba,ca) (a,b,c) ->
+  let pipeline ~ocluster repos distro gen_tags =
+    let opam_images, ocaml_images, archive_image =
+      let arch_results =
+        let arches = Conf.arches_for ~distro in
+        List.map (Arch.pipeline ~ocluster ~repos ~distro) arches in
+      List.fold_left (fun (aa,ba,ca) (a,b,c) ->
           let ca = match ca,c with Some v, _ -> Some v | None, v -> v in
-          a::aa, b::ba, ca) ([], [], None) arch_results in
-      let ocaml_images =
-        all_switches ocaml_images |> List.filter_map @@ fun switch ->
-        let images = List.filter_map (Switch_map.find_opt switch) ocaml_images in
-        if images = [] then None
-        else (
-          let full_tag = Tag.v distro ~switch in
-          let tags =
-            let distro_aliases = aliases_of distro in
-            (* Push the image as e.g. debian-10-ocaml-4.09 and debian-ocaml-4.09 *)
-            let tags = full_tag :: List.map (Tag.v ~switch) distro_aliases in
-            if switch <> Ocaml_version.Releases.latest then tags
-            else (
-              (* For every distro, also create a link to the latest OCaml compiler.
-                 e.g. debian-9 -> debian-9-ocaml-4.09 *)
-              let tags = Tag.v_alias distro :: tags in
-              (* If [distro] is the latest version of that distribution, make an alias like
-                 debian -> debian-10-ocaml-4.09 *)
-              let tags = List.map Tag.v_alias distro_aliases @ tags in
-              (* The top-level alias: latest -> debian-10-ocaml-4.09 *)
-              if distro <> master_distro then tags
-              else Tag.latest :: tags
-            )
-          in
-          (* Fmt.pr "Aliases: %s -> %a@." full_tag Fmt.(Dump.list string) (List.sort String.compare tags); *)
-          let pushes = List.map (fun tag -> Docker.push_manifest ?auth:Conf.auth ~tag images |> Current.ignore_value) tags in
-          Some (full_tag, Current.all pushes)
-        )
+          a::aa, b::ba, ca) ([], [], None) arch_results
+    in
+    let (multiarch_images, ocaml_images) =
+      all_switches ocaml_images |> List.filter_map @@ begin fun switch ->
+        match List.filter_map (Switch_map.find_opt switch) ocaml_images with
+        | [] -> None
+        | images ->
+           let full_tag = Tag.v distro ~switch in
+           let (multiarch_images, tags) = gen_tags images full_tag switch (aliases_of distro) in
+           let pushes = List.map (fun tag -> Docker.push_manifest ?auth:Conf.auth ~tag images |> Current.ignore_value) tags in
+           Some (multiarch_images, (full_tag, Current.all pushes))
+        end |> List.split
+    in
+    let archive_images =
+      match archive_image with
+      | None -> []
+      | Some image -> [ "archive", Docker.push_manifest ?auth:Conf.auth ~tag:(Tag.archive ()) [image] |> Current.ignore_value ]
+    in
+    let pipeline =
+      Current.all_labelled (
+          ("base", Docker.push_manifest ?auth:Conf.auth ~tag:(Tag.v distro) opam_images |> Current.ignore_value)
+          :: ocaml_images
+          @ archive_images)
+    in
+    multiarch_images, pipeline
+
+  let linux_pipeline ~ocluster repos distro =
+    let distro_label = Dockerfile_distro.tag_of_distro distro in
+    let repos = label distro_label repos in
+    Current.collapse ~key:"distro" ~value:distro_label ~input:repos @@
+      let gen_tags _images full_tag switch distro_aliases =
+        let tags =
+          (* Push the image as e.g. debian-10-ocaml-4.09 and debian-ocaml-4.09 *)
+          let tags = full_tag :: List.map (Tag.v ~switch) distro_aliases in
+          if switch <> Ocaml_version.Releases.latest then tags
+          else (
+            (* For every distro, also create a link to the latest OCaml compiler.
+               e.g. debian-9 -> debian-9-ocaml-4.09 *)
+            let tags = Tag.v_alias distro :: tags in
+            (* If [distro] is the latest version of that distribution, make an alias like
+               debian -> debian-10-ocaml-4.09 *)
+            let tags = List.map Tag.v_alias distro_aliases @ tags in
+            (* The top-level alias: latest -> debian-10-ocaml-4.09 *)
+            if distro <> master_distro then tags
+            else Tag.latest :: tags
+          )
+        in
+        (* Fmt.pr "Aliases: %s -> %a@." full_tag Fmt.(Dump.list string) (List.sort String.compare tags); *)
+        Switch_map.empty, tags
       in
-      let archive_images =
-        match archive_image with
-        | None -> []
-        | Some image -> [ "archive", Docker.push_manifest ?auth:Conf.auth ~tag:(Tag.archive ()) [image] |> Current.ignore_value ]
+      let (_multiarch_images, pipeline) = pipeline ~ocluster repos distro gen_tags in
+      pipeline
+
+  let windows_distro_pipeline ~ocluster repos distro_label distro_versions =
+    let distro_pipeline multiarches distro =
+      let gen_tags images full_tag switch distro_aliases =
+        let tags =
+          (* Push the image as e.g. windows-mingw-1809-ocaml-4.09 and windows-mingw-ltsc2019-ocaml-4.09  *)
+          let tags = full_tag :: List.map (Tag.v ~switch) distro_aliases in
+          if switch <> Ocaml_version.Releases.latest then tags
+          else (
+            (* For every distro, also create a link to the latest OCaml compiler.
+               e.g. windows-mingw-1809 -> windows-mingw-1809-ocaml-4.09 *)
+            Tag.v_alias distro :: tags
+          )
+        in
+        (* Fmt.pr "Aliases: %s -> %a@." full_tag Fmt.(Dump.list string) (List.sort String.compare tags); *)
+        Switch_map.add switch images Switch_map.empty, tags
       in
-      Current.all_labelled (
-       ("base", Docker.push_manifest ?auth:Conf.auth ~tag:(Tag.v distro) opam_images |> Current.ignore_value)
-        :: ocaml_images
-        @ archive_images)
-    )
+      let (multiarch_images, pipeline) = pipeline ~ocluster repos distro gen_tags in
+      let multiarch_images =
+        let update images = function None -> Some images | Some images' -> Some (images @ images') in
+        let fold switch images acc = Switch_map.update switch (update images) acc in
+        let fold_left acc images = Switch_map.fold fold acc images in
+        List.fold_left fold_left multiarches multiarch_images
+      in
+      (multiarch_images, pipeline)
+    in
+    let multiarch, pipelines = List.fold_left_map distro_pipeline Switch_map.empty distro_versions in
+    let pushes =
+      Switch_map.fold (fun switch images pushes ->
+        let full_tag = Printf.sprintf "%s:%s-ocaml-%s" Conf.public_repo distro_label (Tag.tag_of_compiler switch) in
+        let tags =
+          let tags = [full_tag] in
+          if switch <> Ocaml_version.Releases.latest then tags
+          else Printf.sprintf "%s:%s" Conf.public_repo distro_label :: tags
+        in
+        (* Fmt.pr "Aliases: %s -> %a@." full_tag Fmt.(Dump.list string) (List.sort String.compare tags); *)
+        let pushes' = List.map (fun tag -> Docker.push_manifest ?auth:Conf.auth ~tag images |> Current.ignore_value) tags in
+        (full_tag, Current.all pushes') :: pushes)
+      multiarch []
+    in
+    Current.(collapse ~key:"distro" ~value:distro_label ~input:repos (all ((all_labelled pushes) :: pipelines)))
+
+  let windows_pipeline ~ocluster repos mingw msvc cygwin =
+    List.filter_map (fun (distro_label, distros) ->
+        match distros with
+        | [] -> None
+        | distro_versions ->
+           let repos = label distro_label repos in
+           windows_distro_pipeline ~ocluster repos distro_label distro_versions |> Option.some)
+      [("windows-mingw", mingw); ("windows-msvc", msvc); ("cygwin", cygwin)]
+
+  (* The main pipeline. Builds images for all supported distribution, compiler version and architecture combinations. *)
+  let v ~ocluster repos =
+    let linux, mingw, msvc, cygwin = Conf.distros |> List.fold_left (fun (linux, mingw, msvc, cygwin) distro ->
+      let os_family = Dockerfile_distro.os_family_of_distro distro in
+      match os_family with
+      | `Linux -> distro :: linux, mingw, msvc, cygwin
+      | `Cygwin -> linux, mingw, msvc, distro :: cygwin
+      | `Windows ->
+         match distro with
+         | `Windows (`Mingw, _) -> linux, distro :: mingw, msvc, cygwin
+         | `Windows (`Msvc, _) -> linux, mingw, distro :: msvc, cygwin
+         | _ -> assert false) ([], [], [], [])
+    in
+    let pipelines =
+      List.rev_map (linux_pipeline ~ocluster repos) linux
+      @ windows_pipeline ~ocluster repos mingw msvc cygwin in
+    Current.all pipelines
 end
 
 module Real = Make(struct
diff --git a/src/tag.mli b/src/tag.mli
index 39f03427..1a9607cd 100644
--- a/src/tag.mli
+++ b/src/tag.mli
@@ -1,3 +1,7 @@
+val tag_of_compiler : Ocaml_version.t -> string
+(** [tag_of_compiler switch] returns a tag identifying the compiler by
+    its version and variants. *)
+
 val v : ?arch:Ocaml_version.arch -> ?switch:Ocaml_version.t -> Dockerfile_distro.t -> string
 (** [v ?arch ?switch distro] is the Docker tag to use for an image built on [distro] and [arch]
     with OCaml compiler [switch] installed. If [switch] is [None] then this is a base image