“long long long” is too long for gcc?

Apparently, somewhere in your Promela code you have specified a 'long long long' type. Here is how a simple C program misbehaves with such a declaration:

ebg@ebg$ cat ~/foo.c
#include <stdio.h>

extern int
main (void)
{
  long long long x;

  printf ("%lld", x>>32);
}
ebg@ebg$ gcc -o foo ~/foo.c
/Users/ebg/foo.c: In function 'main':
/Users/ebg/foo.c:6: error: 'long long long' is too long for GCC

Your incorrect use of 'long long long' should be obvious in your *.pml file; but, if you can't find it there, then look in pan.c (or pan.* files).