t/sigfd: add diagnostic for occasional FreeBSD failure

Not 100% sure what's going on, here...

1 files changed, 2 insertions, 1 deletions

diff --git a/t/sigfd.t b/t/sigfd.t
index bb854147..a1ab222c 100644
--- a/t/sigfd.t
+++ b/t/sigfd.t
@@ -47,7 +47,8 @@ SKIP: {
                 kill('HUP', $$) or die "kill $!";
                 PublicInbox::DS->SetPostLoopCallback(sub {}); # loop once
                 PublicInbox::DS->EventLoop;
-                is($hit->{HUP}->{sigfd}, 2, 'HUP sigfd fired in event loop');
+                is($hit->{HUP}->{sigfd}, 2, 'HUP sigfd fired in event loop') or
+                        diag explain($hit); # sometimes fails on FreeBSD 11.x
                 kill('TERM', $$) or die "kill $!";
                 kill('HUP', $$) or die "kill $!";
                 PublicInbox::DS->EventLoop;