dgit: Improve some error messages about changes files

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 4 insertions, 2 deletions

diff --git a/dgit b/dgit
index f826cda..77c85e5 100755
--- a/dgit
+++ b/dgit
@@ -6372,10 +6372,12 @@ END
 	runcmd_ordryrun_local @mergechanges, @changesfiles;
 	my $multichanges = changespat $version,'multi';
 	if (act_local()) {
-	    stat_exists $multichanges or fail "$multichanges: $!";
+	    stat_exists $multichanges
+		or fail "$multichanges unexpectedly not created by build";
 	    foreach my $cf (glob $pat) {
 		next if $cf eq $multichanges;
-		rename "$cf", "$cf.inmulti" or fail "$cf\{,.inmulti}: $!";
+		rename "$cf", "$cf.inmulti" or
+		    fail "install new changes $cf\{,.inmulti}: $!";
 	    }
 	}
 	$result = $multichanges;