feat: some windows fixes (wip)

.bazelrc

@@ -4,6 +4,14 @@ common --enable_bzlmod
 
 common --test_output=errors
 
+# Windows settings
+startup --windows_enable_symlinks
+
+# Point tools such as coursier (used in rules_jvm_external) to Bazel's downloaded JDK
+# suggested in https://github.com/bazelbuild/rules_jvm_external/issues/445
+common --repo_env=JAVA_HOME=../bazel_tools/jdk
+common --action_env=JAVA_HOME=../bazel_tools/jdk
+
 # Define value used by tests
 common --define=SOME_VAR=SOME_VALUE
 
@@ -17,7 +25,9 @@ common --per_file_copt=external/.*protobuf.*@--PROTOBUF_WAS_NOT_SUPPOSED_TO_BE_B
 common --host_per_file_copt=external/.*protobuf.*@--PROTOBUF_WAS_NOT_SUPPOSED_TO_BE_BUILT
 
 # Don't try and auto detect the cc toolchain, as we use our own gcc toolchains.
-common --repo_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
+# Except on windows, where we use msvc
+common:linux --repo_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
+common:macos --repo_env=BAZEL_DO_NOT_DETECT_CPP_TOOLCHAIN=1
 
 # Don't link against libunwind on macos as it causes linking failures (https://github.com/bazel-contrib/toolchains_llvm/pull/346)
 common:macos --@toolchains_llvm//toolchain/config:libunwind=False

BUILD.bazel

@@ -8,6 +8,11 @@ load("//uv/private/manifest:defs.bzl", "gazelle_python_manifest")
 # gazelle:exclude examples/django
 # gazelle:map_kind bzl_library bzl_library @bazel_lib//:bzl_library.bzl
 
+not_windows = select({
+    "@platforms//os:windows": ["@platforms//:incompatible"],
+    "//conditions:default": [],
+})
+
 gazelle_python_manifest(
     name = "gazelle_python_manifest",
     hub = "pypi",
@@ -19,6 +24,7 @@ gazelle_python_manifest(
 gazelle(
     name = "gazelle",
     gazelle = "@multitool//tools/gazelle",
+    target_compatible_with = not_windows,
 )
 
 compile_pip_requirements(

MODULE.bazel

@@ -13,6 +13,12 @@ bazel_dep(name = "platforms", version = "1.0.0")
 bazel_dep(name = "rules_python", version = "1.0.0")
 bazel_dep(name = "with_cfg.bzl", version = "0.11.0")
 
+python_stdlib_list = use_extension("@rules_python//python:extensions.bzl", "python_stdlib_list")
+use_repo(
+    python_stdlib_list,
+    "python_stdlib_list",
+)
+
 tools = use_extension("//py:extensions.bzl", "py_tools")
 tools.rules_py_tools()
 use_repo(tools, "rules_py_tools")
@@ -30,8 +36,10 @@ use_repo(
     toml,
     "toml2json_aarch64_linux_gnu",
     "toml2json_aarch64_osx_libsystem",
+    "toml2json_aarch64_windows_msvc",
     "toml2json_x86_64_linux_gnu",
     "toml2json_x86_64_osx_libsystem",
+    "toml2json_x86_64_windows_msvc",
 )
 
 host = use_extension("//uv/private/host:extension.bzl", "host_platform")
@@ -409,7 +417,7 @@ register_toolchains("@rust_toolchains//:all")
 bazel_dep(name = "xz", version = "5.4.5.bcr.5")
 bazel_dep(name = "zstd", version = "1.5.7")
 bazel_dep(name = "bzip2", version = "1.0.8.bcr.2")
-bazel_dep(name = "rules_rs", version = "0.0.7")
+bazel_dep(name = "rules_rs", version = "0.0.13")
 
 crate = use_extension(
     "@rules_rs//rs:extensions.bzl",

bazel/platforms/config/defs.bzl

@@ -9,6 +9,7 @@ cpus = ["aarch64", "x86_64"]
 os_to_linker = {
     "linux": ["unknown"],
     "macos": ["unknown"],
+    "windows": ["unknown"],
 }
 
 platforms = [

bazel/rust/multi_platform_rust_binaries.bzl

@@ -11,6 +11,7 @@ TARGET_TRIPLES = [
     ("aarch64_unknown_linux_gnu", "linux_aarch64"),
     ("x86_64_apple_darwin", "macos_x86_64"),
     ("aarch64_apple_darwin", "macos_aarch64"),
+    ("x86_64_pc_windows_msvc", "windows_x86_64"),
 ]
 
 # Map a Rust naming scheme to a custom name.
@@ -40,12 +41,19 @@ def multi_platform_rust_binaries(name, target, name_scheme = TARGET_NAMING_SCHEM
 
     for (target_triple, target_platform) in target_triples:
         target_naming = name_scheme.get(target_triple, target_triple)
-
+        not_windows = select({
+            "@platforms//os:windows": ["@platforms//:incompatible"],
+            "//conditions:default": [],
+        })
+        target_compatible_with = not_windows
+        if target_platform.startswith("windows"):
+            target_compatible_with = ["@platforms//os:windows"]
         transition_build = "{}_{}_build".format(bin, target_naming)
         platform_transition_filegroup(
             name = transition_build,
             srcs = [target],
             target_platform = "//bazel/platforms:{}".format(target_platform),
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 
@@ -54,13 +62,15 @@ def multi_platform_rust_binaries(name, target, name_scheme = TARGET_NAMING_SCHEM
             name = "{}_copy".format(copy_name),
             src = transition_build,
             out = copy_name,
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 
         bin_sha256 = "{}_bin_hash".format(copy_name)
         hashes(
             name = bin_sha256,
             src = copy_name,
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 
@@ -71,6 +81,7 @@ def multi_platform_rust_binaries(name, target, name_scheme = TARGET_NAMING_SCHEM
             renames = {copy_name: bin},
             attributes = pkg_attributes(mode = "0744"),
             strip_prefix = "/",
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 
@@ -84,13 +95,15 @@ def multi_platform_rust_binaries(name, target, name_scheme = TARGET_NAMING_SCHEM
             # Why is -1 not the default :/
             # This also sets the modified time in UTC.
             stamp = -1,
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 
         pkged_sha256 = "{}_pkged_hash".format(copy_name)
         hashes(
             name = pkged_sha256,
             src = pkged,
+            target_compatible_with = target_compatible_with,
             tags = ["release"],
         )
 

e2e/cases/repository-rule-deps-299/.bazelrc

@@ -5,3 +5,6 @@ common --enable_bzlmod
 
 # The imports=[".."] only works properly when this matches the python toolchain major version.
 common --@aspect_rules_py//py:interpreter_version=3.11.6
+
+# Windows settings
+startup --windows_enable_symlinks

examples/py_venv/BUILD.bazel

@@ -4,6 +4,11 @@ load("@rules_oci//oci:defs.bzl", "oci_image", "oci_load")
 load("//py:defs.bzl", "py_image_layer")
 load("//py/unstable:defs.bzl", "py_venv", "py_venv_binary")
 
+not_windows = select({
+    "@platforms//os:windows": ["@platforms//:incompatible"],
+    "//conditions:default": [],
+})
+
 expand_template(
     name = "stamped",
     stamp_substitutions = {
@@ -82,10 +87,12 @@ platform_transition_filegroup(
         "@platforms//cpu:arm64": ":aarch64_linux",
         "@platforms//cpu:x86_64": ":x86_64_linux",
     }),
+    target_compatible_with = not_windows,
 )
 
 oci_load(
     name = "load",
     image = ":platform_image",
     repo_tags = ["py_venv_example:latest"],
+    target_compatible_with = not_windows,
 )

py/BUILD.bazel

@@ -36,6 +36,7 @@ bzl_library(
         "//py/private:virtual",
         "//py/private/py_venv",
         "@aspect_bazel_lib//lib:utils",
+        "@aspect_bazel_lib//lib:windows_utils",
     ],
 )
 

py/private/py_binary.bzl

@@ -2,6 +2,7 @@
 
 load("@aspect_bazel_lib//lib:expand_make_vars.bzl", "expand_locations", "expand_variables")
 load("@aspect_bazel_lib//lib:paths.bzl", "BASH_RLOCATION_FUNCTION", "to_rlocation_path")
+load("@aspect_bazel_lib//lib:windows_utils.bzl", "create_windows_native_launcher_script")
 load("@rules_python//python:defs.bzl", "PyInfo")
 load("//py/private:py_library.bzl", _py_library = "py_library_utils")
 load("//py/private:py_semantics.bzl", _py_semantics = "semantics")
@@ -15,6 +16,7 @@ def _dict_to_exports(env):
     ]
 
 def _py_binary_rule_impl(ctx):
+    is_windows = ctx.target_platform_has_constraint(ctx.attr._windows_constraint[platform_common.ConstraintValueInfo])
     venv_toolchain = ctx.toolchains[VENV_TOOLCHAIN]
     py_toolchain = _py_semantics.resolve_toolchain(ctx)
 
@@ -69,10 +71,15 @@ def _py_binary_rule_impl(ctx):
             attribute_name = "env",
         )
 
-    executable_launcher = ctx.actions.declare_file(ctx.attr.name)
+    print(py_toolchain.python)
+    print(py_toolchain.runfiles_interpreter)
+    print(py_toolchain.python.path)
+    print(to_rlocation_path(ctx, py_toolchain.python))
+
+    bash_launcher = ctx.actions.declare_file(ctx.attr.name)
     ctx.actions.expand_template(
         template = ctx.file._run_tmpl,
-        output = executable_launcher,
+        output = bash_launcher,
         substitutions = {
             "{{BASH_RLOCATION_FN}}": BASH_RLOCATION_FUNCTION,
             "{{INTERPRETER_FLAGS}}": " ".join(py_toolchain.flags + ctx.attr.interpreter_options),
@@ -91,6 +98,8 @@ def _py_binary_rule_impl(ctx):
         is_executable = True,
     )
 
+    launcher = create_windows_native_launcher_script(ctx, bash_launcher) if is_windows else bash_launcher
+
     srcs_depset = _py_library.make_srcs_depset(ctx)
 
     runfiles = _py_library.make_merged_runfiles(
@@ -100,6 +109,8 @@ def _py_binary_rule_impl(ctx):
             srcs_depset,
         ] + virtual_resolution.srcs + virtual_resolution.runfiles,
         extra_runfiles = [
+            launcher,
+            bash_launcher,
             site_packages_pth_file,
         ],
         extra_runfiles_depsets = [
@@ -116,11 +127,11 @@ def _py_binary_rule_impl(ctx):
     return [
         DefaultInfo(
             files = depset([
-                executable_launcher,
+                bash_launcher,
                 main,
-                site_packages_pth_file,
+                site_packages_pth_file
             ]),
-            executable = executable_launcher,
+            executable = launcher,
             runfiles = runfiles,
         ),
         PyInfo(
@@ -194,6 +205,7 @@ A collision can occur when multiple packages providing the same file are install
     "_allowlist_function_transition": attr.label(
         default = "@bazel_tools//tools/allowlists/function_transition_allowlist",
     ),
+    "_windows_constraint": attr.label(default = "@platforms//os:windows"),
 })
 
 _attrs.update(**_py_library.attrs)
@@ -222,6 +234,7 @@ py_base = struct(
     toolchains = [
         PY_TOOLCHAIN,
         VENV_TOOLCHAIN,
+        "@bazel_tools//tools/sh:toolchain_type",
     ],
     cfg = python_version_transition,
 )

py/tests/py_image_layer/BUILD.bazel

@@ -4,6 +4,11 @@ load("@rules_oci//oci:defs.bzl", "oci_image", "oci_load")
 load("//py:defs.bzl", "py_binary", "py_image_layer")
 load("asserts.bzl", "assert_tar_listing")
 
+not_windows = select({
+    "@platforms//os:windows": ["@platforms//:incompatible"],
+    "//conditions:default": [],
+})
+
 platform(
     name = "aarch64_linux",
     constraint_values = [
@@ -39,6 +44,7 @@ platform_transition_filegroup(
     name = "platform_layers",
     srcs = [":my_app_layers"],
     target_platform = ":x86_64_linux",
+    target_compatible_with = not_windows,
 )
 
 # FIXME(Bazel 8+): This listing needs to be updated/
@@ -64,6 +70,7 @@ platform_transition_filegroup(
         "@platforms//cpu:arm64": ":aarch64_linux",
         "@platforms//cpu:x86_64": ":x86_64_linux",
     }),
+    target_compatible_with = not_windows,
 )
 
 # To build the image and load it into it into a local runtime:
@@ -79,6 +86,7 @@ platform_transition_filegroup(
     name = "amd64_image",
     srcs = [":image"],
     target_platform = ":x86_64_linux",
+    target_compatible_with = not_windows,
 )
 
 container_structure_test(

py/tests/py_venv_image_layer/BUILD.bazel

@@ -5,6 +5,11 @@ load("//py:defs.bzl", "py_image_layer")
 load("//py/tests/py_image_layer:asserts.bzl", "assert_tar_listing")
 load("//py/unstable:defs.bzl", "py_venv_binary")
 
+not_windows = select({
+    "@platforms//os:windows": ["@platforms//:incompatible"],
+    "//conditions:default": [],
+})
+
 platform(
     name = "arm64_linux",
     constraint_values = [
@@ -56,6 +61,7 @@ platform_transition_filegroup(
     name = "amd64_layers",
     srcs = [":my_app_layers"],
     target_platform = ":amd64_linux",
+    target_compatible_with = not_windows,
 )
 
 # FIXME(Bazel 8+): This listing needs to be updated/
@@ -70,6 +76,7 @@ platform_transition_filegroup(
     name = "arm64_layers",
     srcs = [":my_app_layers"],
     target_platform = ":arm64_linux",
+    target_compatible_with = not_windows,
 )
 
 # FIXME(Bazel 8+): This listing needs to be updated/
@@ -95,6 +102,7 @@ platform_transition_filegroup(
         "@platforms//cpu:arm64": ":arm64_linux",
         "@platforms//cpu:x86_64": ":amd64_linux",
     }),
+    target_compatible_with = not_windows,
 )
 
 # To build the image and load it into it into a local runtime:
@@ -110,6 +118,7 @@ platform_transition_filegroup(
     name = "amd64_image",
     srcs = [":image"],
     target_platform = ":amd64_linux",
+    target_compatible_with = not_windows,
 )
 
 container_structure_test(
@@ -133,6 +142,7 @@ platform_transition_filegroup(
     name = "arm64_image",
     srcs = [":image"],
     target_platform = ":arm64_linux",
+    target_compatible_with = not_windows,
 )
 
 container_structure_test(

py/tests/virtual/django/BUILD.bazel

@@ -8,6 +8,7 @@ compile_pip_requirements(
     name = "requirements",
     requirements_in = "requirements.in",
     requirements_txt = "requirements.txt",
+    requirements_windows = "requirements_windows.txt",
 )
 
 # Test fixture: a library with an external dependency

py/tests/virtual/django/requirements.txt

@@ -56,3 +56,7 @@ typing-extensions==4.8.0 \
     --hash=sha256:8f92fc8806f9a6b641eaa5318da32b44d401efaac0f6678c9bc448ba3605faa0 \
     --hash=sha256:df8e4339e9cb77357558cbdbceca33c303714cf861d1eef15e1070055ae8b7ef
     # via asgiref
+tzdata==2025.2 \
+    --hash=sha256:1a403fada01ff9221ca8044d701868fa132215d84beb92242d9acd2147f667a8 \
+    --hash=sha256:b60a638fcc0daffadf82fe0f57e53d06bdec2f36c4df66280ae79bce6bd6f2b9
+    # via django