User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0
Just a heads up about <https://gerrit.libreoffice.org/c/core/+/131943>
"Drop support for OpenGL denylist on X11", which would drop that
denylist and the underlying glxtest machinery, for the reasons stated
there. Please speak up if you see any issues with that.