Unable to start Pix in COSMIC Desktop, DBUS error.

[virtadpt]

Distribution

Arch Linux, 20251231

Package version

3.4.9

Frequency

Always

Bug description

Note: This is a new development on my end. I'd been using Pix since early 2025 without trouble.

I updated my system to the latest and greatest of everything on 31 December 2025 to give the COSMIC Desktop a try and discovered that Pix starts up for only a second or two (displaying the file window for my home directory) before crashing. Running Pix from the command line results in the following output:

{15:48:52 @ Sun Jan 04}
[drwho @ windbringer ~] () $ pix

(pix:990593): Gtk-WARNING **: 15:51:09.668: Creating a portal monitor failed:
GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: No such interface
“org.freedesktop.portal.Inhibit” on object at path /org/freedesktop/portal/desktop
libpng error: Read Error
Aborted                    (core dumped) pix

I've been able to reproduce this with v3.4.9 as well as v3.4.4 from Git.

Steps to reproduce

• Open a terminal window.
• pix

Expected behavior

Pix should start up, display the file selector window for $HOME, and not crash.

Additional information

No response

[mtwebster]

libpng error: Read Error

This could be what's causing the crash - the Inhibit stuff is troubling but I don't know enough about cosmic desktop to be sure (though I don't think xdg-desktop-portal-cosmic implements Inhibit yet). I'd still try and double-check you've got all the components COSMIC requires to run.

Can you provide a backtrace?

[virtadpt]

I installed COSMIC with the documented procedure right after doing a full system update. It pulled in quite a few dependencies. I know libpng is there because I was interrogating the package yesterday to make sure everything was in place (plus, other software I use that's linked against libpng is working as expected).

How would you like me to get you a backtrace? Run it in gdb? Or is there another procedure that would get you useful information?

[virtadpt]

Thread 1 "pix" received signal SIGABRT, Aborted.
0x00007ffff6a9890c in ?? () from /usr/lib/libc.so.6
(gdb) bt
#0  0x00007ffff6a9890c in ??? () at /usr/lib/libc.so.6
#1  0x00007ffff6a3e3a0 in raise () at /usr/lib/libc.so.6
#2  0x00007ffff6a2557a in abort () at /usr/lib/libc.so.6
#3  0x00007ffff708e04c in ??? () at /usr/lib/libpng16.so.16
#4  0x00007ffff709042a in png_error () at /usr/lib/libpng16.so.16
#5  0x00007ffff7092b39 in ??? () at /usr/lib/libpng16.so.16
#6  0x00007ffff7095cdb in png_read_info () at /usr/lib/libpng16.so.16
#7  0x0000555555625b7b in gnome_desktop_thumbnail_is_valid ()
#8  0x0000555555625e32 in gnome_desktop_thumbnail_factory_lookup ()
#9  0x00005555556141ba in gth_thumb_loader_load ()
#10 0x00005555555bfdee in ??? ()
#11 0x00007ffff7d6cf8d in ??? () at /usr/lib/libglib-2.0.so.0
#12 0x00007ffff7d6e657 in ??? () at /usr/lib/libglib-2.0.so.0
#13 0x00007ffff7d6e865 in g_main_context_iteration ()
    at /usr/lib/libglib-2.0.so.0
#14 0x00007ffff7c197d6 in g_application_run () at /usr/lib/libgio-2.0.so.0
#15 0x00005555555861f0 in main ()

[virtadpt]

I switched back to LXqt and it still happens.