Load the workspace config in two stages

So that we don't fail immediately if the context definition is wrong
for instnace.

Signed-off-by: Jeremie Dimino <jeremie@dimino.org>

Author: jeremiedimino

bin/common.ml

@@ -156,14 +156,14 @@ let set_common ?log_file c =
      can interpret errors in the workspace file. *)
   print_entering_message c;
   Dune_rules.Workspace.Clflags.set c.workspace_config;
-  let workspace =
+  let config =
     (* Here we make the assumption that this computation doesn't yield. *)
     Fiber.run
-      (Memo.Build.run (Dune_rules.Workspace.workspace ()))
+      (Memo.Build.run (Dune_rules.Workspace.workspace_config ()))
       ~iter:(fun () -> assert false)
   in
   let config =
-    Dune_config.adapt_display workspace.config
+    Dune_config.adapt_display config
       ~output_is_a_tty:(Lazy.force Ansi_color.stderr_supports_color)
   in
   Dune_config.init config;

src/dune_lang/decoder.ml

@@ -264,6 +264,10 @@ let capture ctx state =
   let f t = result ctx (t ctx state) in
   (f, [])
 
+let lazy_ t =
+  let+ f = capture in
+  lazy (f t)
+
 let end_of_list (Values (loc, cstr, _)) =
   match cstr with
   | None ->

src/dune_lang/decoder.mli

@@ -124,6 +124,9 @@ val repeat1 : 'a t -> 'a list t
 (** Capture the rest of the input for later parsing *)
 val capture : ('a t -> 'a) t
 
+(** Delay the parsing of the rest of the input *)
+val lazy_ : 'a t -> 'a Lazy.t t
+
 (** [enter t] expect the next element of the input to be a list and parse its
     contents with [t]. *)
 val enter : 'a t -> 'a t