Make detection of dev tool lock dirs untracked

Signed-off-by: Marek Kubica <[email protected]>

Author: Leonidas-from-XIV

src/dune_rules/format_rules.ml

@@ -33,8 +33,10 @@ end
 
 module Ocamlformat = struct
   let dev_tool_lock_dir_exists () =
-    let path = Lock_dir.dev_tool_source_lock_dir Ocamlformat in
-    Source_tree.find_dir path >>| Option.is_some
+    Ocamlformat
+    |> Lock_dir.dev_tool_source_lock_dir
+    |> Path.source
+    |> Path.Untracked.exists
   ;;
 
   (* Config files for ocamlformat. When these are changed, running
@@ -129,7 +131,7 @@ let gen_rules_output
   let loc = Format_config.loc config in
   let dir = Path.Build.parent_exn output_dir in
   let alias_formatted = Alias.fmt ~dir:output_dir in
-  let* ocamlformat_is_locked = Ocamlformat.dev_tool_lock_dir_exists () in
+  let ocamlformat_is_locked = Ocamlformat.dev_tool_lock_dir_exists () in
   let setup_formatting file =
     (let input_basename = Path.Source.basename file in
      let input = Path.Build.relative dir input_basename in

test/blackbox-tests/test-cases/pkg/ocamlformat/ocamlformat-dev-tool-fails-to-build.t

@@ -15,7 +15,7 @@ It fails during the build because of missing OCamlFormat module.
   $ DUNE_CONFIG__LOCK_DEV_TOOL=enabled dune fmt
   Solution for _build/dev-tools.locks/ocamlformat:
   - ocamlformat.0.26.4
-  File "dev-tools.locks/ocamlformat/ocamlformat.pkg", line 4, characters 6-10:
+  File "_build/dev-tools.locks/ocamlformat/ocamlformat.pkg", line 4, characters 6-10:
   4 |  (run dune build -p %{pkg-self:name} @install))
             ^^^^
   Error: Logs for package ocamlformat