This is issue 157 upstream: https://gitlab.freedesktop.org/xorg/lib/libx11/-/issues/157 Apparently, they do not want to revert it. So, should Debian build with --disable-thread-safety-constructor, at least for a while? (Remember that this bug will soon block other packages from migrating, e.g. thunderbird 102.) -richy. -- Richard B. Kreckel <https://in.terlu.de/~kreckel/>