Hello Ludovic, Ludovic Courtès <l...@gnu.org> writes:
> Hello, > > Ludovic Courtès <l...@gnu.org> skribis: > >> A simple thing would be to somehow get libssh to pass POLLIN | POLLRDHUP >> instead of just POLLIN. > > Reported here: > > https://www.libssh.org/archive/libssh/2019-01/0000000.html > > A fix has been proposed by upstream and should be committed shortly. > >> Additionally, we could change Guile-SSH so that we can specify a timeout >> when reading from a channel. > > Turns out we can set a per-session timeout, which we already do (see > #:timeout in ‘open-ssh-session’ in (guix scripts offload)) but > ‘ssh_channel_read’ would ignore it and instead pass an infinite timeout > to poll(2): > > https://www.libssh.org/archive/libssh/2019-01/0000001.html > > This issue happens to be fixed in libssh 0.8.x, so I upgraded our libssh > package in commit a8b0556ea1e439c89dc1ba33c8864e8b9b811f08. > > (That still doesn’t tell us why our ‘guix offload’ processes would > occasionally be stuck but at least it ensures the build farm keeps > making progress even when that happens.) > > Ludo’. Seems the patch in the response at the URL you linked is awaiting some feedback/review. Is this the reason 'guix substitute' hangs for so long when the substitute server is down? (like 1 minute or so). Maxim
