Bug 2262476

The journal had messages which started with Plasma 5.93.0 around 20 s after I started it like 
kded6[1771]: QProcess: Destroyed while process ("/usr/libexec/kf6/kconf_update") is still running.

I ran /usr/libexec/kf6/kconf_update in Konsole, and it finished after about 30 s. When I logged out and in to Plasma after that, the desktop icons appeared after about 2 s. /usr/libexec/kf6/kconf_update still being running 20 s into startup might've delayed the desktop icons from being shown.

I had to run /usr/libexec/kf6/kconf_update in Konsole separately for each of two users on the system to work around the problem. The problem started again two days ago right after a dnf offline upgrade which included kwin-5.93.0-2.fc40 and plasma-integration-5.93.0-3.fc40. I ran /usr/libexec/kf6/kconf_update in Konsole again for both users and the problem stopped. /usr/libexec/kf6/kconf_update took about 30-40 s to run in Konsole the first time I ran it, and its output had a line like QProcess: Destroyed while process ("/usr/bin/python3") is still running when that happened. /usr/libexec/kf6/kconf_update took about 1 s to run in Konsole the second and third time I ran it in Konsole after today's update as my user, and it didn't have the python containing line I mentioned. The output of kconf_update kded6 in the journal was about 20 s after starting Plasma when the problem happened and about 3-5 s after when it didn't. The lines like kded6[1771]: QProcess: Destroyed while process ("/usr/libexec/kf6/kconf_update") is still running. didn't appear in the journal after I ran /usr/libexec/kf6/kconf_update in Konsole for that user, but other messages from kconf_update and kded6 appeared about 3-5 s after starting Plasma when the problem didn't happen.

To make the problem start happening again, I logged out of Plasma, switched to another VT and reinstalled kwin with sudo dnf reinstall kwin*. When I logged in to Plasma after that, the problem happened. I ran Konsole before the desktop icons appeared and ps aux | grep python showed a process /usr/bin/python3 /usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py I ran strace /usr/libexec/kf6/kconf_update in Konsole. The strace output showed that kconf_update was waiting on /usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py for about 30 s after which it timed out and was killed with the error QProcess: Destroyed while process ("/usr/bin/python3") is still running.

openat(AT_FDCWD, "/usr/share/kconf_update/kwin.upd", O_RDONLY|O_CLOEXEC) = 4
statx(4, "", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=571, ...}) = 0
statx(4, "", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=571, ...}) = 0
statx(4, "", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT|AT_EMPTY_PATH, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0644, stx_size=571, ...}) = 0
read(4, "# SPDX-FileCopyrightText: 2023 N"..., 16384) = 571
read(4, "", 15813)                      = 0
statx(AT_FDCWD, "/home/matt/.local/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd130) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/home/matt/.local/share/flatpak/exports/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd130) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/var/lib/flatpak/exports/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd130) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/usr/local/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd130) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0755, stx_size=869, ...}) = 0
getcwd("/home/matt", 4096)              = 11
statx(AT_FDCWD, "/home/matt/.local/bin/python3", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd070) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/home/matt/bin/python3", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd070) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/usr/lib64/ccache/python3", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd070) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/usr/local/bin/python3", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, 0x7ffe30dcd070) = -1 ENOENT (No such file or directory)
statx(AT_FDCWD, "/usr/bin/python3", AT_STATX_SYNC_AS_STAT|AT_NO_AUTOMOUNT, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_attributes=0, stx_mode=S_IFREG|0755, stx_size=15976, ...}) = 0
access("/usr/bin/python3", X_OK)        = 0
pipe2([5, 6], O_CLOEXEC)                = 0
pipe2([7, 8], O_CLOEXEC)                = 0
pipe2([9, 10], O_CLOEXEC)               = 0
pipe2([11, 12], O_CLOEXEC)              = 0
write(3, "\1\0\0\0\0\0\0\0", 8)         = 8
waitid(P_PIDFD, 2147483647, NULL, WNOHANG|WEXITED, NULL) = -1 EBADF (Bad file descriptor)
clone(child_stack=0x7ffe30dcd130, flags=CLONE_VM|CLONE_PIDFD|CLONE_VFORK|SIGCHLD, parent_tid=[13]) = 69375
close(12)                               = 0
close(5)                                = 0
fcntl(6, F_GETFL)                       = 0x1 (flags O_WRONLY)
fcntl(6, F_SETFL, O_WRONLY|O_NONBLOCK)  = 0
close(8)                                = 0
fcntl(7, F_GETFL)                       = 0 (flags O_RDONLY)
fcntl(7, F_SETFL, O_RDONLY|O_NONBLOCK)  = 0
close(10)                               = 0
fcntl(9, F_GETFL)                       = 0 (flags O_RDONLY)
fcntl(9, F_SETFL, O_RDONLY|O_NONBLOCK)  = 0
ppoll([{fd=11, events=POLLIN}], 1, {tv_sec=60, tv_nsec=0}, NULL, 8) = 1 ([{fd=11, revents=POLLHUP}], left {tv_sec=59, tv_nsec=999998295})
read(11, "", 16)                        = 0
write(3, "\1\0\0\0\0\0\0\0", 8)         = 8
close(11)                               = 0
write(3, "\1\0\0\0\0\0\0\0", 8)         = 8
write(3, "\1\0\0\0\0\0\0\0", 8)         = 8
write(3, "\1\0\0\0\0\0\0\0", 8)         = 8
ppoll([{fd=-1}, {fd=7, events=POLLIN}, {fd=9, events=POLLIN}, {fd=13, events=POLLIN}], 4, {tv_sec=60, tv_nsec=0}, NULL, ) = ? ERESTARTNOHAND (To be restarted if no handler)
--- SIGWINCH {si_signo=SIGWINCH, si_code=SI_KERNEL} ---
ppoll([{fd=-1}, {fd=7, events=POLLIN}, {fd=9, events=POLLIN}, {fd=13, events=POLLIN}], 4, {tv_sec=18, tv_nsec=330338566}, NULL, 8) = 0 (Timeout)
write(2, "QProcess: Destroyed while proces"..., 73QProcess: Destroyed while process ("/usr/bin/python3") is still running.
) = 73
kill(69375, SIGKILL)                    = 0
ppoll([{fd=-1}, {fd=7, events=POLLIN}, {fd=9, events=POLLIN}, {fd=13, events=POLLIN}], 4, {tv_sec=30, tv_nsec=0}, NULL, 8) = 3 ([{fd=7, revents=POLLHUP}, {fd=9, revents=POLLHUP}, {fd=13, revents=POLLIN}], left {tv_sec=29, tv_nsec=998870093})
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_KILLED, si_pid=69375, si_uid=1000, si_status=SIGKILL, si_utime=2 /* 0.02 s */, si_stime=0} ---

I attached the strace output at https://bugs.kde.org/show_bug.cgi?id=480758#c5 ps aux | grep python also showed /usr/bin/python3 /usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py while strace /usr/libexec/kf6/kconf_update was waiting. So /usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py timing out might've led kconf_update to time out and kded6 and the desktop icons to be delayed by 20 s.

Vlad Zahorodnii wrote patches for this problem one of which drops /usr/share/kconf_update/kwin-6.0-overview-activities-shortcuts.py from kwin at https://invent.kde.org/plasma/kwin/-/merge_requests/5129

This bug appears to have been reported against 'rawhide' during the Fedora Linux 42 development cycle.
Changing version to 42.

This problem was fixed in kwin 6.0 while Rawhide was F40.