dgit: Improve some error messages about changes files

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

diff --git a/dgit b/dgit
index f826cdaae1ffe82fdc14ed33dd7cc4a31760314e..77c85e5de47e64aade8f6c0f194332d72eb975cb 100755 (executable)
--- 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;