Avoiding

cc1: warnings being treated as errors
exc.c: In function 'ExcRaise':
exc.c:186: warning: passing arg 1 of 'Longjmp' from incompatible pointer type
gmake[3]: *** [exc.o] Error 1

Now we have:
#if defined (JMP_BUF)
        longjmp(efp->context, 1);
#else
        siglongjmp(efp->context, 1);
#endif