From mboxrd@z Thu Jan  1 00:00:00 1970
From: ludo@gnu.org (Ludovic =?UTF-8?Q?Court=C3=A8s?=)
Subject: bug#29335: 'guix publish' workers occasionally crash
Date: Sun, 19 Nov 2017 23:48:47 +0100
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ludo@gnu.org (Ludovic Court=C3=A8s) skribis:

> On berlin I=E2=80=99ve noticed that the =E2=80=98guix publish=E2=80=99 wo=
rkers would
> occasionally stop working: the main thread would keep replying to HTTP
> requests, but the worker threads would no longer do anything, and would
> leave behind them a bunch of .tmp files in /var/cache/guix/publish.
>
> I captured the output of =E2=80=98guix publish=E2=80=99 (guix-0.13.0-8.35=
7ab93) and the
> only clue I have is this:
>
> GET /6kl9ydqmgklcqhxswg6v5isq5n1ih5gp.narinfo
> In guix/workers.scm:
>      74:9  2 (_)
>     78:32  1 (_ srfi-34 #<condition &nix-connection-error [file: "/v=E2=
=80=A6>)
> In unknown file:
>            0 (make-stack #t)
> ERROR: In procedure make-stack:
> ERROR: Throw to key `srfi-34' with args `(#<condition &nix-connection-err=
or [file: "/var/guix/daemon-socket/socket" errno: 9] 3ba2ea0>)'.
> GET /fgiih42mg2sr82mbmzf56grvrf021im6.narinfo

Good news, this is fixed in 85f4f7b79040d982c6a655c898b4cd00d868fa9c.

This could be reproduced by running =E2=80=98guix publish=E2=80=99 with 10 =
workers or
more, and then triggering nar compression en masse with =E2=80=98guix weath=
er=E2=80=99.

EBADF was due to a race condition in zlib.scm when closing gzip output
ports:

          ;; 'gzclose' closes the underlying file descriptor.  'close-port'
          ;; calls close(2) and gets EBADF, which we swallow.
          (gzclose gzfile)
          (ignore-EBADF (close-port port)))

There was a window after the =E2=80=98gzclose=E2=80=99 call during which th=
e file
descriptor for GZFILE and PORT above could be reused for something else,
and then =E2=80=98close-port=E2=80=99 would close it.

Thanks,
Ludo=E2=80=99.