Make package private libraries visible when installed

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

src/dune_rules/dune_file.ml

@@ -1854,15 +1854,27 @@ module Library_redirect = struct
 
     let of_lib (lib : Library.t) : t option =
       let open Option.O in
-      let* public = lib.public in
-      if Lib_name.equal (Lib_name.of_local lib.name) (snd public.name) then
+      let* public_name =
+        match lib.visibility with
+        | Public plib -> Some plib.name
+        | Private None -> None
+        | Private (Some package) ->
+          let loc, name = lib.name in
+          Some
+            ( loc
+            , Lib_name.of_string
+                (sprintf "%s.__private__.%s"
+                   (Package.Name.to_string package.name)
+                   (Lib_name.Local.to_string name)) )
+      in
+      if Lib_name.equal (Lib_name.of_local lib.name) (snd public_name) then
         None
       else
         Some
           { loc = Loc.none
           ; project = lib.project
           ; old_name = lib.name
-          ; new_public_name = public.name
+          ; new_public_name = public_name
           }
   end
 end

src/dune_rules/scope.ml

@@ -77,8 +77,13 @@ module DB = struct
               let named p loc = Option.some_if (name = p) loc in
               match stanza with
               | Library (_, { buildable = { loc; _ }; visibility = Public p; _ })
+                ->
+                named (Dune_file.Public_lib.name p) loc
               | Deprecated_library_name
-                  { loc; old_public_name = { public = p; _ }; _ } ->
+                  { Dune_file.Library_redirect.loc
+                  ; old_name = (p, _)
+                  ; _
+                  } ->
                 Option.some_if (name = Dune_file.Public_lib.name p) loc
               | _ -> None)
         with