SUMMARY Downloaded cursor themes should are stored in ~/.icons/ instead of ~/.local/share/icons/ This means that they' aren't accessible by Flatpak apps. STEPS TO REPRODUCE 1. Download a cursor theme 2. ls ~/.icons/ 3. ls ~/.local/share/icons/ OBSERVED RESULT In 2. the new theme is shown, but not in 3. Flatpak apps don't use the downloaded cursor theme EXPECTED RESULT The new theme should be shown in 3. Flatpak apps use the downloaded cursor theme SOFTWARE/OS VERSIONS KDE Plasma Version: 6.3.5 KDE Frameworks Version: 6.14.0 Qt Version: 6.9.0 ADDITIONAL INFORMATION The path is set in https://github.com/KDE/plasma-workspace/blob/v6.3.5/kcms/cursortheme/kcmcursortheme.cpp#L435 And also checked in https://github.com/KDE/plasma-workspace/blob/v6.3.5/kcms/cursortheme/kcmcursortheme.cpp#L71 and https://github.com/KDE/plasma-workspace/blob/v6.3.5/kcms/cursortheme/kcmcursortheme.cpp#L186 Cursor themes are already being looked for in ~/.local/share/icons/ by the kcm, so no migration routine should be needed.
See https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/1233 for a previous attempt at this
That merge request mentions libxcb-cursor not supporting ~/.local/share/icons This was added to it in https://cgit.freedesktop.org/xcb/util-cursor/commit/?id=d28a3227eb9e4bdeeb4dd93017c298808bbe62ee (see also https://gitlab.freedesktop.org/xorg/lib/libxcb-cursor/-/issues/12). Which means that future libxcb-cursor (aka xcb-util-cursor) 0.1.6 will make it possible to restore the commit from that merge request to fix this.