Dune Pins itself

src/dune_pkg/dune_dep.ml

@@ -6,3 +6,6 @@ let version =
   let major, minor = Dune_lang.Stanza.latest_version in
   OpamPackage.Version.of_string @@ sprintf "%d.%d" major minor
 ;;
+
+let package = OpamPackage.create (Package_name.to_opam_package_name name) version
+let opam_file = OpamFile.OPAM.create package

src/dune_pkg/dune_dep.mli

@@ -1,2 +1,4 @@
 val name : Package_name.t
 val version : OpamPackage.Version.t
+val package : OpamPackage.t
+val opam_file : OpamFile.OPAM.t

src/dune_pkg/opam_repo.ml

@@ -134,7 +134,7 @@ let load_opam_package_from_dir ~(dir : Path.t) package =
   | false -> None
   | true ->
     let files_dir = Some (Paths.files_dir package) in
-    Some (Resolved_package.local_fs package ~dir ~opam_file_path ~files_dir)
+    Some (Resolved_package.local_fs package ~dir ~opam_file_path ~files_dir ~url:None)
 ;;
 
 let load_packages_from_git rev_store opam_packages =
@@ -151,7 +151,8 @@ let load_packages_from_git rev_store opam_packages =
         ~opam_file:(Rev_store.File.path opam_file)
         ~opam_file_contents
         rev
-        ~files_dir:(Some files_dir))
+        ~files_dir:(Some files_dir)
+        ~url:None)
 ;;
 
 let all_packages_versions_in_dir loc ~dir opam_package_name =

src/dune_pkg/opam_solver.ml

@@ -348,6 +348,8 @@ module Context = struct
   let user_restrictions : t -> OpamPackage.Name.t -> OpamFormula.version_constraint option
     =
     fun t pkg ->
+    (* This isn't really needed because we already pin dune, but it seems to
+       help the error messages *)
     if Package_name.equal Dune_dep.name (Package_name.of_opam_package_name pkg)
     then Some (`Eq, t.dune_version)
     else None
@@ -1658,6 +1660,18 @@ let solve_lock_dir
       ~selected_depopts
       ~portable_lock_dir
   =
+  let pinned_packages =
+    Package_name.Map.update pinned_packages Dune_dep.name ~f:(function
+      | None -> Some Resolved_package.dune
+      | Some p ->
+        let loc = Resolved_package.loc p in
+        User_error.raise
+          ~loc
+          [ Pp.text
+              "Dune cannot be pinned. The currently running version is the only one that \
+               may be used"
+          ])
+  in
   let pinned_package_names = Package_name.Set.of_keys pinned_packages in
   let stats_updater = Solver_stats.Updater.init () in
   let context =

src/dune_pkg/pinned_package.ml

@@ -66,39 +66,38 @@ let resolve_package { Local_package.loc; url = loc_url, url; name; version; orig
       (Package_name.to_opam_package_name name)
       (Package_version.to_opam_package_version version)
   in
-  let+ resolved_package =
-    let* mount = Mount.of_opam_url loc_url url in
-    let* opam_file_path, files_dir = discover_layout loc name mount in
-    match Mount.backend mount with
-    | Path dir ->
-      Resolved_package.local_fs package ~dir ~opam_file_path ~files_dir |> Fiber.return
-    | Git rev ->
-      let+ opam_file_contents =
-        (* CR-rgrinberg: not efficient to make such individual calls *)
-        Mount.read mount opam_file_path
-        >>| function
-        | Some p -> p
-        | None ->
-          let files =
-            match Path.Local.parent opam_file_path with
-            | None -> []
-            | Some parent ->
-              Rev_store.At_rev.directory_entries rev parent ~recursive:false
-              |> Rev_store.File.Set.to_list_map ~f:Rev_store.File.path
-          in
-          Code_error.raise
-            ~loc
-            "unable to find file"
-            [ "opam_file_path", Path.Local.to_dyn opam_file_path
-            ; "files", Dyn.list Path.Local.to_dyn files
-            ]
-      in
-      Resolved_package.git_repo
-        package
-        ~opam_file:opam_file_path
-        ~opam_file_contents
-        rev
-        ~files_dir
-  in
-  Resolved_package.set_url resolved_package url
+  let* mount = Mount.of_opam_url loc_url url in
+  let* opam_file_path, files_dir = discover_layout loc name mount in
+  match Mount.backend mount with
+  | Path dir ->
+    Resolved_package.local_fs package ~dir ~opam_file_path ~files_dir ~url:(Some url)
+    |> Fiber.return
+  | Git rev ->
+    let+ opam_file_contents =
+      (* CR-rgrinberg: not efficient to make such individual calls *)
+      Mount.read mount opam_file_path
+      >>| function
+      | Some p -> p
+      | None ->
+        let files =
+          match Path.Local.parent opam_file_path with
+          | None -> []
+          | Some parent ->
+            Rev_store.At_rev.directory_entries rev parent ~recursive:false
+            |> Rev_store.File.Set.to_list_map ~f:Rev_store.File.path
+        in
+        Code_error.raise
+          ~loc
+          "unable to find file"
+          [ "opam_file_path", Path.Local.to_dyn opam_file_path
+          ; "files", Dyn.list Path.Local.to_dyn files
+          ]
+    in
+    Resolved_package.git_repo
+      package
+      ~opam_file:opam_file_path
+      ~opam_file_contents
+      rev
+      ~files_dir
+      ~url:(Some url)
 ;;

src/dune_pkg/resolved_package.ml

@@ -4,22 +4,38 @@ type extra_files =
   | Inside_files_dir of Path.t option
   | Git_files of Path.Local.t option * Rev_store.At_rev.t
 
-type nonrec t =
+type rest =
   { opam_file : OpamFile.OPAM.t
   ; package : OpamPackage.t
   ; extra_files : extra_files
   ; loc : Loc.t
   ; dune_build : bool
   }
 
-let dune_build t = t.dune_build
-let loc t = t.loc
-let package t = t.package
-let opam_file t = t.opam_file
+type nonrec t =
+  | Dune
+  | Rest of rest
+
+let dune = Dune
+
+let dune_build = function
+  | Dune -> false
+  | Rest t -> t.dune_build
+;;
+
+let loc = function
+  | Dune -> Loc.none
+  | Rest t -> t.loc
+;;
 
-let set_url t url =
-  let opam_file = OpamFile.OPAM.with_url (OpamFile.URL.create url) t.opam_file in
-  { t with opam_file }
+let package = function
+  | Dune -> Dune_dep.package
+  | Rest t -> t.package
+;;
+
+let opam_file = function
+  | Dune -> Dune_dep.opam_file
+  | Rest t -> t.opam_file
 ;;
 
 let add_opam_package_to_opam_file package opam_file =
@@ -28,37 +44,44 @@ let add_opam_package_to_opam_file package opam_file =
   |> OpamFile.OPAM.with_name (OpamPackage.name package)
 ;;
 
-let read_opam_file package ~opam_file_path ~opam_file_contents =
-  Opam_file.read_from_string_exn ~contents:opam_file_contents opam_file_path
-  |> add_opam_package_to_opam_file package
+let read_opam_file package ~opam_file_path ~opam_file_contents ~url =
+  let opam_file =
+    Opam_file.read_from_string_exn ~contents:opam_file_contents opam_file_path
+    |> add_opam_package_to_opam_file package
+  in
+  match url with
+  | None -> opam_file
+  | Some url -> OpamFile.OPAM.with_url (OpamFile.URL.create url) opam_file
 ;;
 
-let git_repo package ~opam_file ~opam_file_contents rev ~files_dir =
+let git_repo package ~opam_file ~opam_file_contents rev ~files_dir ~url =
   let opam_file_path = Path.of_local opam_file in
-  let opam_file = read_opam_file package ~opam_file_path ~opam_file_contents in
+  let opam_file = read_opam_file package ~opam_file_path ~opam_file_contents ~url in
   let loc = Loc.in_file opam_file_path in
-  { dune_build = false
-  ; loc
-  ; package
-  ; opam_file
-  ; extra_files = Git_files (files_dir, rev)
-  }
+  Rest
+    { dune_build = false
+    ; loc
+    ; package
+    ; opam_file
+    ; extra_files = Git_files (files_dir, rev)
+    }
 ;;
 
-let local_fs package ~dir ~opam_file_path ~files_dir =
+let local_fs package ~dir ~opam_file_path ~files_dir ~url =
   let opam_file_path = Path.append_local dir opam_file_path in
   let files_dir = Option.map files_dir ~f:(Path.append_local dir) in
   let opam_file =
     let opam_file_contents = Io.read_file ~binary:true opam_file_path in
-    read_opam_file package ~opam_file_path ~opam_file_contents
+    read_opam_file package ~opam_file_path ~opam_file_contents ~url
   in
   let loc = Loc.in_file opam_file_path in
-  { dune_build = false
-  ; loc
-  ; package
-  ; extra_files = Inside_files_dir files_dir
-  ; opam_file
-  }
+  Rest
+    { dune_build = false
+    ; loc
+    ; package
+    ; extra_files = Inside_files_dir files_dir
+    ; opam_file
+    }
 ;;
 
 (* Scan a path recursively down retrieving a list of all files together with their
@@ -92,18 +115,26 @@ let local_package ~command_source loc opam_file opam_package =
   in
   let opam_file = add_opam_package_to_opam_file opam_package opam_file in
   let package = OpamFile.OPAM.package opam_file in
-  { dune_build; opam_file; package; loc; extra_files = Inside_files_dir None }
+  Rest { dune_build; opam_file; package; loc; extra_files = Inside_files_dir None }
 ;;
 
 open Fiber.O
 
 let get_opam_package_files resolved_packages =
   let indexed = List.mapi resolved_packages ~f:(fun i w -> i, w) |> Int.Map.of_list_exn in
   let from_dirs, from_git =
-    Int.Map.partition_map indexed ~f:(fun (resolved_package : t) ->
-      match resolved_package.extra_files with
-      | Git_files (files_dir, rev) -> Right (files_dir, rev)
-      | Inside_files_dir dir -> Left dir)
+    let _dune, without_dune =
+      Int.Map.partition_map indexed ~f:(function
+        | Dune -> Left ()
+        | Rest t -> Right t)
+    in
+    let dirs, git =
+      Int.Map.partition_map without_dune ~f:(fun (resolved_package : rest) ->
+        match resolved_package.extra_files with
+        | Git_files (files_dir, rev) -> Right (files_dir, rev)
+        | Inside_files_dir dir -> Left dir)
+    in
+    dirs, git
   in
   let+ from_git =
     if Int.Map.is_empty from_git

src/dune_pkg/resolved_package.mli

@@ -5,22 +5,24 @@ type t
 val package : t -> OpamPackage.t
 val opam_file : t -> OpamFile.OPAM.t
 val loc : t -> Loc.t
-val set_url : t -> OpamUrl.t -> t
 val dune_build : t -> bool
+val dune : t
 
 val git_repo
   :  OpamPackage.t
   -> opam_file:Path.Local.t
   -> opam_file_contents:string
   -> Rev_store.At_rev.t
   -> files_dir:Path.Local.t option
+  -> url:OpamUrl.t option
   -> t
 
 val local_fs
   :  OpamPackage.t
   -> dir:Path.t
   -> opam_file_path:Path.Local.t
   -> files_dir:Path.Local.t option
+  -> url:OpamUrl.t option
   -> t
 
 val local_package

test/blackbox-tests/test-cases/pkg/implicit-dune-constraint.t

@@ -6,9 +6,6 @@ dependency.
   $ . ./helpers.sh
   $ mkrepo
 
-  $ mkpkg dune 3.11.0 <<EOF
-  > EOF
-
   $ test() {
   > mkpkg foo <<EOF
   > depends: [ "dune" {<= "$1"} ]
@@ -23,12 +20,17 @@ dependency.
   Selected candidates: foo.0.0.1 x.dev
   - dune -> (problem)
       User requested = 3.XX
+      foo 0.0.1 requires <= 2.0.0
       Rejected candidates:
-        dune.3.XX.0: Incompatible with restriction: = 3.XX
+        dune.3.XX: Incompatible with restriction: <= 2.0.0
   $ test "4.0.0"
   Solution for dune.lock:
   - foo.0.0.1
 
+  $ test "4.0.0" 2>&1 | sed -E 's/3.[0-9]+/3.XX/g'
+  Solution for dune.lock:
+  - foo.0.0.1
+
 Create a fake project and ensure `dune` can be used as a dependency:
   $ cat > dune-project <<EOF
   > (lang dune 3.13)

test/blackbox-tests/test-cases/pkg/pin-stanza/pin-dune.t

@@ -0,0 +1,34 @@
+Pinning dune itself
+
+  $ . ../helpers.sh
+
+  $ mkrepo
+  $ add_mock_repo_if_needed
+
+# CR-someday rgrinberg: ideally, this source shouldn't be necessary and we
+# should disqualify this pin without resolving any sources
+
+  $ mkdir _extra_source
+  $ cat >_extra_source/dune-project <<EOF
+  > (lang dune 3.12)
+  > (package (name dune))
+  > EOF
+
+  $ cat >dune-project <<EOF
+  > (lang dune 3.13)
+  > (pin
+  >  (url "file://$PWD/_extra_source")
+  >  (package (name dune)))
+  > (package
+  >   (name main))
+  > EOF
+
+For now, pinning dune is not allowed:
+
+  $ dune pkg lock
+  File "dune-project", line 4, characters 1-22:
+  4 |  (package (name dune)))
+       ^^^^^^^^^^^^^^^^^^^^^
+  Error: Dune cannot be pinned. The currently running version is the only one
+  that may be used
+  [1]

test/blackbox-tests/test-cases/pkg/unsatisfied-version-constraint-on-dune.t

@@ -22,8 +22,12 @@ project:
 
 Solve the dependencies:
   $ dune pkg lock 2>&1 | sed -E 's/"3.[0-9]+"/"3.XX"/'
-  Error: The current version of Dune does not satisfy the version constraints
-  for Dune in this project's dependencies.
-  Details:
-  Found version "3.XX" of package "dune" which doesn't satisfy the required
-  version constraint "< 3.0"
+  Error: Unable to solve dependencies for the following lock directories:
+  Lock directory dune.lock:
+  Couldn't solve the package dependency formula.
+  Selected candidates: foo.dev
+  - dune -> (problem)
+      User requested = 3.21
+      foo dev requires < 3.0
+      Rejected candidates:
+        dune.3.21: Incompatible with restriction: < 3.0