From ffebade4b474be2b14117fe92d3ca72813d2d938 Mon Sep 17 00:00:00 2001
From: Gaëtan Gilbert
Date: Wed, 14 Oct 2020 16:54:49 +0200
Subject: Fix anomaly when importing a functor

Fix #13162
---
 test-suite/bugs/closed/bug_13162.v |  7 +++++++
 vernac/vernacentries.ml            | 10 ++++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 test-suite/bugs/closed/bug_13162.v

diff --git a/test-suite/bugs/closed/bug_13162.v b/test-suite/bugs/closed/bug_13162.v
new file mode 100644
index 0000000000..eacc8980a9
--- /dev/null
+++ b/test-suite/bugs/closed/bug_13162.v
@@ -0,0 +1,7 @@
+
+Module Type T. End T.
+Module F (X:T). End F.
+Fail Import F.
+(* Error: Anomaly "Uncaught exception Not_found." *)
+
+Fail Import T.
diff --git a/vernac/vernacentries.ml b/vernac/vernacentries.ml
index 0d3f38d139..b125a86636 100644
--- a/vernac/vernacentries.ml
+++ b/vernac/vernacentries.ml
@@ -957,9 +957,15 @@ let interp_filter_in m = function
 
 let vernac_import export refl =
   let import_mod (qid,f) =
-    let m = try Nametab.locate_module qid
+    let loc = qid.loc in
+    let m = try
+        let m = Nametab.locate_module qid in
+        let () = if Modops.is_functor (Global.lookup_module m).Declarations.mod_type
+          then CErrors.user_err ?loc Pp.(str "Cannot import functor " ++ pr_qualid qid ++ str".")
+        in
+        m
       with Not_found ->
-        CErrors.user_err Pp.(str "Cannot find module " ++ pr_qualid qid)
+        CErrors.user_err ?loc Pp.(str "Cannot find module " ++ pr_qualid qid)
     in
     let f = interp_filter_in m f in
     Declaremods.import_module f ~export m
-- 
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