tmux troubles with port_associate on pkgsrc illumos

[whorfin]

Greetings
And apologies if this is "the wrong place", I took the "please file it" request to heart, and the mailinglist link was broken.
Using

https://pkgsrc.joyent.com/packages/SmartOS/trunk/x86_64/All

on

$ uname -a
SunOS serverbox 5.11 omnios-r151030-5bd7739fe4 i86pc i386 i86pc illumos

and having installed tmux-3.2

I noticed that vim "fakeclip" package was badly misbehaving. And I tracked it down to a very simple repro case:

$ tmux load-buffer test.txt
[warn] port_associate: Not owner

I don't always get the port_associate message, but it's not just a warning - the tmux command hangs and must be manually killed. Sometimes it works fine.
Something is annoyingly, intermittently amiss.

tmux show-buffer is similarly affected, although I have found that this always works:

$ tmux show-buffer

while redirection sometimes triggers the port_associate hanging "warning"

$ tmux show-buffer >/tmp/busted
[warn] port_associate: Not owner
[warn] port_associate: Not owner

Cheers

[jclulow]

That seems unusual. From the manual page for port_associate(3C):

       The port_associate() function will fail if:

       EACCES
                  The source argument is PORT_SOURCE_FILE and, Search permission
                  is denied on a component of path prefix or the file exists and
                  the permissions, corresponding to the events argument, are
                  denied.

...

Have you tried tracing the arguments to the port_associate() call to see what's being associated when it fails this way?

[whorfin]

Here are the results of

$ truss -t port_associate tmux load-buffer test.txt >& log.txt

for a "it worked" and an "it hung with the message" case
(The SIGTERM is from me killing the hanging tmux)

00tmux-fail.txt
00tmux-ok.txt

[whorfin]

...I pulled down and built from source various versions from upstream https://github.com/tmux/tmux/releases
tmux-3.2 behaves just as the joyent/pkgsrc version does
tmux-3.1c is similarly broken
tmux-3.0a appears to be OK
so you might want to downgrade the version provided; I will report upstream

[whorfin]

Per the tmux upstream conversation, this appears to be a bug in libevent.
Setting EVENT_NOEVPORT=1 fixes tmux!
This might explain a secondary annoyance of bizarre lockup/hangs-until-timeouts when resizing the enclosing terminal over ssh
A random google hit which points to this being observed in opensolaris long ago would be:
https://forum.transmissionbt.com/viewtopic.php?t=6680&start=15

[pfmooney]

This has been diagnosed as illumos#15036