Subject: bug#33239: 'guix offload' regularly hangs in 'channel-get-exit-status' call

From: Ludovic Courtès <[email-masked]>
Date: Sat, 22 Dec 2018 17:49:49 +0100

[email-masked] (Ludovic Courtès) skribis:

> The ‘guix offload’ processes on berlin regularly hang while calling
> ‘channel-get-exit-status’:
>
> (gdb) bt
> #0  0x00007f299fb330f1 in __GI___poll (fds=0x1dd58c0, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
> #1  0x00007f2994287577 in ssh_poll_ctx_dopoll () from target:/gnu/store/wmpg67bn7i7pqc0p4xjp1npnqixk9znd-libssh-0.7.6/lib/libssh.so.4
> #2  0x00007f29942884d9 in ssh_handle_packets () from target:/gnu/store/wmpg67bn7i7pqc0p4xjp1npnqixk9znd-libssh-0.7.6/lib/libssh.so.4
> #3  0x00007f29942885ad in ssh_handle_packets_termination () from target:/gnu/store/wmpg67bn7i7pqc0p4xjp1npnqixk9znd-libssh-0.7.6/lib/libssh.so.4
> #4  0x00007f2994275080 in ssh_channel_get_exit_status () from target:/gnu/store/wmpg67bn7i7pqc0p4xjp1npnqixk9znd-libssh-0.7.6/lib/libssh.so.4
> #5  0x00007f29946dd11a in guile_ssh_channel_get_exit_status () from target:/gnu/store/i3nfl17wfx7sryq6w15r9wxl7ilmq4rb-guile-ssh-0.11.3/lib/libguile-ssh.so.11
> #6  0x00007f29a1765965 in vm_regular_engine (thread=0x1dd58c0, vp=0x1d4df30, registers=0xffffffff, resume=-1615646479) at vm-engine.c:786

I was able to come up with a reduced test case for Guile-SSH:

  https://github.com/artyom-poptsov/guile-ssh/issues/11

Ludo’.