git-debrebase: Improve error message for convert-from-gbp upstream discrepancy

[dgit.git] / git-debrebase

diff --git a/git-debrebase b/git-debrebase
index 439a10a75de5be17b14998314b849e64da0ab504..13ca472d47881b34361a8c4dc160bc0113d0f47c 100755 (executable)
--- a/git-debrebase
+++ b/git-debrebase
@@ -1627,10 +1627,14 @@ sub cmd_convert_from_gbp () {
 
     my $upsdiff = get_differs $upstream, $old_head;
     if ($upsdiff & D_UPS) {
-       runcmd @git, qw(--no-pager diff),
+       runcmd @git, qw(--no-pager diff --stat),
            $upstream, $old_head,
            qw( -- :!/debian :/);
- fail "upstream ($upstream_spec) and HEAD are not identical in upstream files";
+       fail <<END;
+upstream ($upstream_spec) and HEAD are not
+identical in upstream files.  See diffstat above, or run
+  git diff $upstream_spec HEAD -- :!/debian :/
+END
     }
 
     if (!is_fast_fwd $upstream, $old_head) {