More fun facts:
If, after you start up emacs -q, you immediate quit it, the recipe in #5 still crashes X.
Starting non-X emacs (e.g. `emacs -nw` in a terminal) does not crash X.
Starting multiple terminals does not crash X.
I'm going to try to rebuild Emacs against the current Trusty package set and see if that can provoke the problem.
More fun facts:
If, after you start up emacs -q, you immediate quit it, the recipe in #5 still crashes X.
Starting non-X emacs (e.g. `emacs -nw` in a terminal) does not crash X.
Starting multiple terminals does not crash X.
I'm going to try to rebuild Emacs against the current Trusty package set and see if that can provoke the problem.