Re: pkg/54192: lang/rust build error

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

Has anyone else tried running firefox on a machine with the patch to
kern_lwp.c ? 

I just tried it and firefox sits in 100% CPU usage without displaying a
window.

My guess is that the problems people have been reporting on other lists
with firefox dumping core are related to threads too, this was my reason
for trying the patch.

Firefox expects to be able to do a fork(2) and have the child probe for
features of whatever OpenGL implementation it is linked to. The idea is
that the child can die without affecting the parent. Both child and
parent get killed when I run it though.

The OpenGL probing functions in Mesa use a thread local pointer to
get at a context structure, the child process is getting a pointer
to an invalid structure which is causing it to crash.