fix(pkg): use correct environment for using format rules (ocaml#11155)

The base environment was omitted

Signed-off-by: Rudi Grinberg <[email protected]>

Author: rgrinberg

src/dune_rules/format_rules.ml

@@ -181,6 +181,12 @@ let gen_rules_output
        if ocamlformat_is_locked
        then (
          let { Action_builder.With_targets.build; targets } = rule in
+         let build =
+           let open Action_builder.O in
+           let+ build = build
+           and+ env = Action_builder.of_memo (Pkg_rules.dev_tool_env Ocamlformat) in
+           Action.Full.add_env env build
+         in
          Rule.make ~mode:Standard ~targets build |> Rules.Produce.rule)
        else
          let open Memo.O in

src/dune_rules/pkg_rules.ml

@@ -2140,6 +2140,21 @@ let ocamlpath context =
 let lock_dir_active = Lock_dir.lock_dir_active
 let lock_dir_path = Lock_dir.get_path
 
+let dev_tool_env tool =
+  let package_name = Dune_pkg.Dev_tool.package_name tool in
+  Memo.push_stack_frame ~human_readable_description:(fun () ->
+    Pp.textf
+      "lock directory environment for dev tools %S"
+      (Package.Name.to_string package_name))
+  @@ fun () ->
+  let universe : Package_universe.t = Dev_tool tool in
+  let* db = DB.get universe in
+  Resolve.resolve db (Loc.none, package_name) universe
+  >>| function
+  | `System_provided -> assert false
+  | `Inside_lock_dir pkg -> Pkg.exported_env pkg
+;;
+
 let exported_env context =
   Memo.push_stack_frame ~human_readable_description:(fun () ->
     Pp.textf "lock directory environment for context %S" (Context_name.to_string context))

src/dune_rules/pkg_rules.mli

@@ -25,6 +25,7 @@ val which : Context_name.t -> (Filename.t -> Path.t option Memo.t) Staged.t
 val exported_env : Context_name.t -> Env.t Memo.t
 val ocamlpath : Context_name.t -> Path.t list Memo.t
 val find_package : Context_name.t -> Package.Name.t -> unit Action_builder.t option Memo.t
+val dev_tool_env : Dune_pkg.Dev_tool.t -> Env.t Memo.t
 
 val setup_pkg_install_alias
   :  dir:Path.Build.t