How do I see the logs for the Xwayland server started by Gnome?

fedora xorg gnome wayland

7,563

gnome-shell does indeed start Xwayland with a journal connection. The messages are showing in the journal with a prefix like org.gnome.Shell.desktop[3494]:, where 3494 is the PID of the gnome-shell process.

See 'What does "org.gnome.Shell.desktop[1711]: " mean in the systemd journal?'.

This can be confusing because gnome-shell logs the same way and it can be very noisy; whereas Xwayland can be very quiet. I see that Xwayland does not log any startup messages. I only see messages logging about errors.

You can try to look for Xwayland messages with a trick along the lines

$ journalctl --since=-1month  | grep ': [(]..[)] ' | grep -v gdm-x-session

$ journalctl --since=-1month \
    | grep -E '[(]([^0-9^a-z]){2}[)]' \
    | grep -v gdm-x-session

Mar 18 21:15:45 alan-laptop org.gnome.Shell.desktop[1133]: (EE) failed to read Wayland events: Connection reset by peer
Mar 18 21:48:01 alan-laptop org.gnome.Shell.desktop[3012]: (EE) failed to read Wayland events: Broken pipe
Mar 18 21:50:06 alan-laptop org.gnome.Shell.desktop[2124]: (EE) failed to read Wayland events: Connection reset by peer
Mar 19 11:03:43 alan-laptop org.gnome.Shell.desktop[29640]: (EE) failed to read Wayland events: Broken pipe

7,563

user2948306

Pronouns: he/him (they/them is fine too). If I link to my bug reports (or patches), I'm the one known as Alan Jenkins.

Updated on September 18, 2022

Comments

user2948306 over 1 year

I am using Fedora Workstation 27. Specifically, gnome-session-3.26.1-1.fc27.x86_64.

I know that Xwayland only serves X11 applications, while native Wayland apps are served directly by gnome-shell. I specifically want to look for log messages from the Xwayland server.

The directory ~/.local/share/xorg/ is empty. I have tried the journal:

# journalctl -b /usr/bin/Xwayland
-- Logs begin at Fri 2017-04-21 15:22:01 BST, end at Fri 2018-03-23 23:45:13 GMT. --
-- No entries --

# journalctl -b | grep -i 'wayland.*]: '
#

It doesn't show anything, even though the second approach works fine to search for "gnome-session".

It looks like Xwayland is connected to the journal, through the exact same sockets as gnome-shell. And if you look at the full list of open files with lsof, Xwayland does not have any log file open.

$ lsof -p 20554 | grep " [0-2][ur]"
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1002/gvfs
      Output information may be incomplete.
Xwayland 20554 alan    0r      CHR                1,3      0t0    12290 /dev/null
Xwayland 20554 alan    1u     unix 0x0000000000e7d1ab      0t0  1945828 type=STREAM
Xwayland 20554 alan    2u     unix 0x00000000a0ce92a9      0t0  1945829 type=STREAM
$ lsof -p 20518 | grep " [0-2][ur]"
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1002/gvfs
      Output information may be incomplete.
gnome-she 20518 alan    0r      CHR                1,3       0t0    12290 /dev/null
gnome-she 20518 alan    1u     unix 0x0000000000e7d1ab       0t0  1945828 type=STREAM
gnome-she 20518 alan    2u     unix 0x00000000a0ce92a9       0t0  1945829 type=STREAM

$ lsof -p 20554
Xwayland 20554 alan    0r      CHR                1,3      0t0    12290 /dev/null
Xwayland 20554 alan    1u     unix 0x0000000000e7d1ab      0t0  1945828 type=STREAM
Xwayland 20554 alan    2u     unix 0x00000000a0ce92a9      0t0  1945829 type=STREAM
Xwayland 20554 alan    3u     unix 0x0000000028595a37      0t0  1939422 type=STREAM
Xwayland 20554 alan    4u     unix 0x000000004eb7173c      0t0  1939418 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan    5u     unix 0x00000000db8a25b3      0t0  1939419 /tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan    6u     unix 0x0000000015c66fa0      0t0  1939441 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan    7u  a_inode               0,13        0    11496 [eventpoll]
Xwayland 20554 alan    8u     unix 0x00000000c130aa15      0t0  1944439 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan    9u      CHR              226,0      0t0      692 /dev/dri/card0
Xwayland 20554 alan   10u      CHR              226,0      0t0      692 /dev/dri/card0
Xwayland 20554 alan   11u     unix 0x00000000313e2f4a      0t0  1945251 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   12u     unix 0x000000002c480fb6      0t0  1948769 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   13u     unix 0x00000000fe0b74af      0t0  1946332 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   14u     unix 0x000000008b10aa34      0t0  1946568 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   15u     unix 0x0000000009a83fdb      0t0  1948183 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   16u     unix 0x00000000eca69878      0t0  1948185 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   17u     unix 0x000000003a75c3bb      0t0  1955186 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   18u     unix 0x0000000072d53ca4      0t0  1957059 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   19u     unix 0x000000001efe4b9c      0t0  1948302 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   20u     unix 0x00000000777a260e      0t0  1946959 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   21u     unix 0x00000000925c7157      0t0  1948306 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   22u     unix 0x00000000ae315ead      0t0  1955996 @/tmp/.X11-unix/X0 type=STREAM
Xwayland 20554 alan   23u     unix 0x000000002edc3509      0t0  1948309 @/tmp/.X11-unix/X0 type=STREAM

don_crissti about 6 years

bugs.freedesktop.org/show_bug.cgi?id=101756
user2948306 about 6 years

@don_crissti I found that mess, but it doesn't seem to contain an answer, and I'm pretty sure my full question is specific enough to be answerable.
don_crissti about 6 years

Well, your answer here is pretty much what Daniel Stone answered over there though yours is a bit more detailed.
user2948306 about 6 years

@don_crissti sorry, I don't get it. I can't find anything in what Daniel Stone says there about where the logs from Xwayland go. I don't expect that Xwayland logs are going to tell me everything about wayland as a whole - if that's not clear you may consider it a defect in my question - feedback appreciated as always. But I don't think my answer helps there, so I still don't get what you're saying.
don_crissti about 6 years

Xwayland is not a Wayland server. It is a helper to run X11 clients inside a Wayland session...The Wayland server you are running on the GNOME Wayland session, is the GNOME Shell. GNOME Shell internally uses a library called Mutter, also developed by GNOME. You do not need to search for 'what your Wayland server is', because the answer is that it is GNOME Shell. The binary is called 'gnome-shell'.. The logical conclusion is that any information related to XWayland is to be found in gnome-shell logs.
user2948306 about 6 years

@don_crissti nope. It's an artefact of the implementation, and a kind of annoying one. E.g. if Xwayland was written to call sd_journal_stream_fd() itself, there'd be no conflation with the gnome-shell logs. Xwayland is not built from Gnome; it is built from the Xorg tree. Daniel Stone's answer does not answer the literal question in that bug, because the real question being asked is how to get logs for the display server
user2948306 about 6 years

@don_crissti i.e. the display server which is responsible for mode-setting, opening input devices etc. Hence why his answer is to look at Gnome. I do not fault Daniel at all for emphasizing the question the reporter was repeatedly trying to get info on, over the literal meaning of that specific report.