🚀 go-pugleaf

As has often been pointed out before (comp.lang.c, comp.std.c,
comp.std.unix) about the only thing one can do safely in a signal
handler is set a flag, and return, or cleanup and exit.  (Even the
latter may not be quite safe, but heck, you're exiting...) 

Calling any procedure or touching global data is perilous -- parts of
the C library are not reentrant (malloc for sure) and calling anything
that might call these parts might put your application into a very
confused state.  I don't know how much of Xlib or Xt is re-entrant, I
suspect there are non-re-entrant parts.  (Perhaps a scenario where
Xlib gets interrupted when packing data into a buffer, the signal
handler tries to pack more data into that buffer resulting in an
interleaved mess?)