Nixpkgs: Please also check the log file at "/dev/null" for additional information.

[davidak]

Issue description

My X server crashed during rebuild (https://github.com/NixOS/nixpkgs/issues/44344). While analyzing the situation, i found this funny, but not very helpful message.

Maybe there should actually be a log? Or do we have it in journal and the message is just broken and upstream has to fix it?

gdm-x-session[1473]: (EE) 19: /nix/store/5c0r5ysrx8w9c4mxr2mqpb8c69s34psz-xorg-server-1.19.6/bin/X (_start+0x2a) [0x4241ba]
gdm-x-session[1473]: (EE)
gdm-x-session[1473]: Fatal server error:
gdm-x-session[1473]: (EE) Caught signal 6 (Aborted). Server aborting
gdm-x-session[1473]: (EE)
gdm-x-session[1473]: Please consult the The X.Org Foundation support
gdm-x-session[1473]:          at http://wiki.x.org
gdm-x-session[1473]:  for help.
gdm-x-session[1473]: (EE) Please also check the log file at "/dev/null" for additional information.
...
gdm-x-session[4014]: _XSERVTransSocketUNIXCreateListener: ...SocketCreateListener() failed
gdm-x-session[4014]: _XSERVTransMakeAllCOTSServerListeners: server already running
gdm-x-session[4014]: (--) Log file renamed from "/dev/null" to "/dev/null"
gdm-x-session[4014]: X.Org X Server 1.19.6
gdm-x-session[4014]: Release Date: 2017-12-20
gdm-x-session[4014]: X Protocol Version 11, Revision 0
gdm-x-session[4014]: Build Operating System: Linux 4.9.97 x86_64
gdm-x-session[4014]: Current Operating System: Linux nixos 4.14.55 #1-NixOS SMP Wed Jul 11 14:29:25 UTC 2018 x86_64

Steps to reproduce

1. crash X11
2. see log

Technical details

• system: "x86_64-linux"
• host os: Linux 4.14.59, NixOS, 18.03.133004.a1299c9951b (Impala)
• multi-user?: no
• sandbox: yes
• version: nix-env (Nix) 2.0.4
• channels(root): "nixos-18.03, nixos-hardware, nixos-unstable-18.09pre143771.a8c71037e04"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[xaverdh]

It should be all in the journal logs. See the commit d84741a4bfb6ed2531ec7154479c147d2c9a737c
Although unhelpful, the message about /dev/null is quite funny I agree :-)

[aanderse]

@davidak given this has been fixed can this issue be closed now?

[davidak]

Yes, the journal works.

Maybe there is a more elegant solution than "-logfile" "/dev/null" in 2019? Or should i report it upstream to get a better error message in case journald is used?

Like: "Please also check the logs in the journal."

Right now it's confusing for the user.

[aanderse]

Yeah seems like an upstream thing. Good to close?

[davidak]

Yes, thanks!

I created an upstream issue: https://gitlab.freedesktop.org/xorg/xserver/issues/634