https://bugs.freedesktop.org/show_bug.cgi?id=110214
--- Comment #72 from Diego Viola diego.viola@gmail.com --- (In reply to Michel Dänzer from comment #51)
The working hypothesis is that it's a Mesa regression between 18.3 and 19.0, so that makes sense?
That was a mistake from my part, sorry.
Setting 'export MESA_EXTENSION_OVERRIDE="-GL_ARB_buffer_storage"' after startx still makes xterm work fine even after startx (from a running Xorg session).
Sorry for the confusion.