lock: show failure path

This ought to be useful for diagnosing bugs in -watch.

diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index c0d4d3b35c4a4bbaa5d90c4273eb6cfcc383b6be..ca43682f87adae1fc38b1bab60478f08d69ce064 100644 (file)
--- a/lib/PublicInbox/Lock.pm
+++ b/lib/PublicInbox/Lock.pm
@@ -12,8 +12,9 @@ use Carp qw(croak);
 # PublicInbox::Import already has the lock on its own.
 sub lock_acquire {
        my ($self) = @_;
-       croak 'already locked' if $self->{lockfh};
-       my $lock_path = $self->{lock_path} or return;
+       my $lock_path = $self->{lock_path};
+       croak 'already locked '.($lock_path // '(undef)') if $self->{lockfh};
+       return unless defined($lock_path);
        sysopen(my $lockfh, $lock_path, O_WRONLY|O_CREAT) or
                die "failed to open lock $lock_path: $!\n";
        flock($lockfh, LOCK_EX) or die "lock failed: $!\n";