The underlying bug was fixed in glib and backported in MSYS2:
https://gitlab.gnome.org/GNOME/glib/-/merge_requests/1665
ccache --zero-stats
ccache --show-stats
export CCACHE_DISABLE=true
-# FIXME: introspection disabled for now because of
-# https://gitlab.gnome.org/GNOME/gobject-introspection/-/issues/340
meson \
-Dx11-backend=false \
-Dwayland-backend=false \
-Dwin32-backend=true \
-Dvulkan=disabled \
- -Dintrospection=disabled \
+ -Dintrospection=enabled \
-Dgtk:werror=true \
_build
unset CCACHE_DISABLE