SUMMARY dbus-daemon[4031]: [system] Activating service name='org.kde.powerdevil.discretegpuhelper' requested by ':1.28' (uid=1004 pid=6643 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper) org.kde.powerdevil.discretegpuhelper: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[4031]: [system] Successfully activated service 'org.kde.powerdevil.discretegpuhelper' dbus-daemon[4031]: [system] Activating service name='org.kde.powerdevil.chargethresholdhelper' requested by ':1.28' (uid=1004 pid=6643 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper) org.kde.powerdevil.chargethresholdhelper: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[4031]: [system] Successfully activated service 'org.kde.powerdevil.chargethresholdhelper' dbus-daemon[4031]: [system] Activating service name='org.kde.powerdevil.backlighthelper' requested by ':1.28' (uid=1004 pid=6643 comm="/usr/libexec/org_kde_powerdevil") (using servicehelper) Oct 1 22:02:48 localhost org.kde.powerdevil.backlighthelper: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[4031]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper' STEPS TO REPRODUCE 1. Log into plasma? Buggered if I know. OBSERVED RESULT Warnings in syslog during plasma startup. EXPECTED RESULT No warnings in syslog during plasma startup. SOFTWARE/OS VERSIONS Operating System: Gentoo Linux 2.15 KDE Plasma Version: 6.1.5 KDE Frameworks Version: 6.5.0 Qt Version: 6.7.2 Kernel Version: 6.6.51-gentoo-dist (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION $ locale LANG=en_NZ.UTF-8 LC_CTYPE="en_NZ.UTF-8" LC_NUMERIC="en_NZ.UTF-8" LC_TIME=en_GB.UTF-8 LC_COLLATE="en_NZ.UTF-8" LC_MONETARY="en_NZ.UTF-8" LC_MESSAGES="en_NZ.UTF-8" LC_PAPER="en_NZ.UTF-8" LC_NAME="en_NZ.UTF-8" LC_ADDRESS="en_NZ.UTF-8" LC_TELEPHONE="en_NZ.UTF-8" LC_MEASUREMENT="en_NZ.UTF-8" LC_IDENTIFICATION="en_NZ.UTF-8" LC_ALL= $ locale -a C C.utf8 en_GB en_GB.utf8 en_NZ en_NZ.utf8 en_US en_US.utf8 POSIX # cat /proc/$(pgrep -f org_kde_powerdevil)/environ | strings | grep -E "LANG|LC_" LANG=en_NZ.UTF-8 LC_TIME=en_GB.UTF-8 LANGUAGE=en_GB:en_US
IIRC this was fixed later in Plasma 6.3. Can you upgrade and see if it goes away?
On Plasma 6.3.4, I can confirm this issue. KDE Plasma Version: 6.3.4 KDE Frameworks Version: 6.13.0 Qt Version: 6.8.2 ``` […] org.kde.kded.smart[2748]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. […] org.kde.powerdevil.discretegpuhelper[2888]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[1747]: [system] Successfully activated service 'org.kde.powerdevil.discretegpuhelper' dbus-daemon[1747]: [system] Activating service name='org.kde.powerdevil.chargethresholdhelper' requested by ':1.60' (uid=x pid=2660 comm="/usr/lib/x86_64-linux-gnu/libexec/org_kde_powerdev") (using servicehelper) org.kde.powerdevil.chargethresholdhelper[2895]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[1747]: [system] Successfully activated service 'org.kde.powerdevil.chargethresholdhelper' dbus-daemon[1747]: [system] Activating service name='org.kde.powerdevil.backlighthelper' requested by ':1.60' (uid=x pid=2660 comm="/usr/lib/x86_64-linux-gnu/libexec/org_kde_powerdev") (using servicehelper) org.kde.powerdevil.backlighthelper[2904]: Detected locale "C" with character encoding "ANSI_X3.4-1968", which is not UTF-8. Qt depends on a UTF-8 locale, and has switched to "C.UTF-8" instead. If this causes problems, reconfigure your locale. See the locale(1) manual for more information. dbus-daemon[1747]: [system] Successfully activated service 'org.kde.powerdevil.backlighthelper' ``` As with the OP I am not noticing any bare C locale in output of `locale`, nor in `localectl`, nor in the environ strings of the implicated helper process. Some earlier version of Plasma did fill my `~/.config/plasma-localerc` with a lot of C locales which caused this warning to appear for all user processes (the related bug #438290 tracks missing "C.UTF-8" option in the kcm) but after fixing that, these warnings still appear in the helper processes. Let me know what other information I can provide. Thanks!
OK, thanks!
The C.UTF-8 locale would need to be applied systemwide. Once it is, this should stop happening. I think that *effectively* makes this a duplicate of Bug 438290. *** This bug has been marked as a duplicate of bug 438290 ***