Debugging Wolf3d

If you have problems with wolf3d, you can either turn off the
SDL parachute in order to get a core file (which may leave your
X server in an unusable state).  Otherwise, you can do the
following:

gdb ./wolf3d-sdl
At the gdb prompt:
set args -debug
run
When it segfaults:
bt
quit

And send us the backtrace.