[PATCH 3/3] watch: add per-directory scanning diagnostics

[Eric Wong <e@80x24.org>]

This may help track down problems associated with a single
directory.  Note we emit a separate message for each of the
`new' and `cur' subdirectories of a Maildir.  Full scans only
happen at startup (or manually), so it shouldn't be too noisy
if logging to syslog.

Requested-by: Robin H. Johnson <robbat2@orbis-terrarum.net>
---
 lib/PublicInbox/Watch.pm | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/Watch.pm b/lib/PublicInbox/Watch.pm
index f793d0d8..0520967f 100644
--- a/lib/PublicInbox/Watch.pm
+++ b/lib/PublicInbox/Watch.pm
@@ -590,7 +590,9 @@ sub fs_scan_step {
 		my $dh;
 		if (ref($dir) eq 'ARRAY') { # continue existing
 			($dir, $dh) = @$dir;
-		} elsif (!opendir($dh, $dir)) {
+		} elsif (opendir($dh, $dir)) {
+			warn "# scanning $dir ...\n";
+		} else {
 			warn "W: failed to open $dir: $! (non-fatal)\n";
 			next;
 		}
@@ -602,6 +604,8 @@ sub fs_scan_step {
 		if ($n < 0) {
 			unshift @{$self->{scan_q}}, [ $dir, $dh ];
 			last;
+		} else {
+			warn "# done scanning $dir\n";
 		}
 	}
 	_done_for_now($self);