On 12-08-15 08:18 , Richard Guenther wrote: > 0 is fixed if you have recent enough gdb. > > (gdb) call debug_tree (0) > > as 0 is a null pointer constant. Oh, cool. Progress. GDB folks, would it be hard to figure out that there is a single variant of the called function and trust the user that they are passing the right pointer value? Diego.