lock: show failure path

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

1 files changed, 3 insertions, 2 deletions

diff --git a/lib/PublicInbox/Lock.pm b/lib/PublicInbox/Lock.pm
index c0d4d3b3..ca43682f 100644
--- 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";