Better error message for nested module application.

Fixes #3809.

1 files changed, 3 insertions, 1 deletions

diff --git a/toplevel/himsg.ml b/toplevel/himsg.ml
index 9341f2f70a..5429e6608d 100644
--- a/toplevel/himsg.ml
+++ b/toplevel/himsg.ml
@@ -879,7 +879,9 @@ let explain_label_already_declared l =
   str ("The label "^Label.to_string l^" is already declared.")
 
 let explain_application_to_not_path _ =
-  str "Application of modules is restricted to paths."
+  strbrk "A module cannot be applied to another module application or " ++
+  strbrk "with-expression; you must give a name to the intermediate result " ++
+  strbrk "module first."
 
 let explain_not_a_functor () =
   str "Application of a non-functor."