Re: crash: memcpy, XChangeProperty, XSetTextProperty, XSetWMIconName, x_set_name_internal

[Richard M. Stallman]

    The backtrace seems to indicate that some of the arguments were
    optimized away by GCC and not saved anywhere where GDB can find them.
    So perhaps you will need to examine some other variables whose values
    can give evidence about the arguments.  Alternatively (assuming you
    can reproduce the crash), modify xfns.c to introduce temporary global
    variables, declared `volatile' to avoid optimizations, and put the
    argument values into them just before XSetWMIconName is called.

Or recompile with -O0 -fno-inline so that the optimizations do not
happen.  (I always use -O0 -fno-inline, since that makes debugging
easier.)