sub index_dir {
my ($git_dir) = @_;
-d $git_dir or die "$git_dir does not appear to be a git repository\n";
+
+ system('git', "--git-dir=$git_dir", 'update-server-info') and
+ die "git update-server-info failed for $git_dir";
my $s = PublicInbox::SearchIdx->new($git_dir, 1);
$s->index_sync;
}