mwp and GNOME 42 - stronnag/mwptools GitHub Wiki
Description
GNOME 42 and later (on Wayland) provide patchy support for some of the legacy libraries used by mwp. This may result in some issues, which you may see in system messages if you run mwp from the CLI.
These issues, if any, will also depend on the graphics card e.g. none on NVidia/nouveau, minor on newish Intel, possibly major on older Intel, minor / none on software rendering (VM including WSL/g).
mwp is defenceless here; it's entirely dependent on the behaviour of the distro's system libraries.
Mitigation
Add the following to $HOME/.config/mwp/cmdopts
GDK_BACKEND=x11
e.g. paste the following in a terminal.
if ! grep -e ^GDK_BACKEND=x11 ~/.config/mwp/cmdopts ; then
mkdir -p ~/.config/mwp
echo "GDK_BACKEND=x11" >> ~/.config/mwp/cmdopts
fi