strspn

[Clint Adams]

> With luck, my 135 line program has sufficient context for the problem to 
> show itself.  That'd make it somewhat easier for the gcc maintainers.  I 
> even entertained the idea of building a cross-compiler and debugger to take 
> a look at what the S390 has, from the comfort of my desktop.

You don't need to cross-compile; you can emulate.

 Hercules is an open source software implementation of the mainframe
 System/370 and ESA/390 architectures, in addition to the new 64-bit
 z/Architecture.

Disclaimer: I've never tried it.