Merge pull request #4844 from jonahbeckford/feature-win32-env-cygpath

Cygpath the PATH from opam env

master_changes.md

@@ -261,6 +261,7 @@ users)
   * [BUG] Catch `EACCES` in lock function [#4948 @oandrieu - fix #4944]
   * Permissions: chmod+unlink before copy [#4827 @jonahbeckford @dra27]
   * Support MSYS2: two-phase rsync on MSYS2 to allow MSYS2's behavior of copying rather than symlinking [#4817 @jonahbeckford]
+  * Environment: translate PATH from Windows to Unix during opam env. [#4844 @jonahbeckford]
 
 ## Test
   * Update crowbar with compare functions [#4918 @rjbou]

src/client/opamConfigCommand.ml

@@ -65,15 +65,20 @@ let list t ns =
   OpamStd.Format.align_table |>
   OpamConsole.print_table stdout ~sep:" "
 
+let possibly_unix_path_env_value k v =
+  if k = "PATH" then (Lazy.force OpamSystem.get_cygpath_path_transform) v
+  else v
+
 let rec print_env = function
   | [] -> ()
   | (k, v, comment) :: r ->
     if OpamConsole.verbose () then
       OpamStd.Option.iter (OpamConsole.msg ": %s;\n") comment;
     if not (List.exists (fun (k1, _, _) -> k = k1) r) || OpamConsole.verbose ()
-    then
+    then (
+      let v' = possibly_unix_path_env_value k v in
       OpamConsole.msg "%s='%s'; export %s;\n"
-        k (OpamStd.Env.escape_single_quotes v) k;
+        k (OpamStd.Env.escape_single_quotes v') k);
     print_env r
 
 let rec print_csh_env = function
@@ -82,9 +87,10 @@ let rec print_csh_env = function
     if OpamConsole.verbose () then
       OpamStd.Option.iter (OpamConsole.msg ": %s;\n") comment;
     if not (List.exists (fun (k1, _, _) -> k = k1) r) || OpamConsole.verbose ()
-    then
+    then (
+      let v' = possibly_unix_path_env_value k v in
       OpamConsole.msg "setenv %s '%s';\n"
-        k (OpamStd.Env.escape_single_quotes v);
+        k (OpamStd.Env.escape_single_quotes v'));
     print_csh_env r
 
 let print_sexp_env env =
@@ -130,7 +136,8 @@ let rec print_fish_env env =
          (* This function assumes that `v` does not include any variable
           * expansions and that the directory names are written in full. See the
           * opamState.ml for details *)
-         set_arr_cmd k v
+         let v' = possibly_unix_path_env_value k v in
+         set_arr_cmd k v'
        | "MANPATH" ->
          manpath_cmd v
        | _ ->

src/core/opamSystem.ml

@@ -485,6 +485,28 @@ let get_cygpath_function =
     let f = Lazy.from_val (fun x -> x) in
     fun ~command:_ -> f
 
+let apply_cygpath_path_transform path =
+  let r =
+    OpamProcess.run
+      (OpamProcess.command ~name:(temp_file "command") ~verbose:false "cygpath" ["--path"; "--"; path])
+  in
+  OpamProcess.cleanup ~force:true r;
+  if OpamProcess.is_success r then
+    List.hd r.OpamProcess.r_stdout
+  else
+    OpamConsole.error_and_exit `Internal_error "Could not apply cygpath --path to %s" path
+
+let get_cygpath_path_transform =
+  (* We are running in a functioning Cygwin or MSYS2 environment if and only
+     if `cygpath` is in the PATH. *)
+  if Sys.win32 then
+    lazy (
+      match resolve_command "cygpath" with
+      | Some _ -> apply_cygpath_path_transform
+      | None -> fun x -> x)
+  else
+    Lazy.from_val (fun x -> x)
+
 let runs = ref []
 let print_stats () =
   match !runs with

src/core/opamSystem.mli

@@ -190,6 +190,12 @@ val resolve_command: ?env:string array -> ?dir:string -> string -> string option
     the identity function otherwise. *)
 val get_cygpath_function: command:string -> (string -> string) lazy_t
 
+(** Returns a function which should be applied to a PATH environment variable
+    if in a functioning Cygwin or MSYS2 environment, translating the Windows or a
+    Unix PATH variable into a Unix PATH variable. Returns the identity function
+    otherwise. *)
+val get_cygpath_path_transform: (string -> string) lazy_t
+
 (** [command cmd] executes the command [cmd] in the correct OPAM
     environment. *)
 val command: ?verbose:bool -> ?env:string array -> ?name:string ->