> I still think it's a bad solution, though; it's imposing special > semantics for process execution in libiberty, rather than the normal > ones that you would expect from the OS.
Doing that is part of the purpose of libiberty. If the OS does something unusual, we try to make it act in a conforming way, so that the rest of the tools need not worry about the OS differences. Adding support for #! scripts is one of the ways we can make MinGW more conforming (Cygwin and DJGPP already support #!) to the norm.
