This requires some updates to OSProcessPlugin (a primitive for the dup2() system call) and to OSProcess. I'm not done yet, but I'll try to get this cleaned up and posted by this weekend.
you don't really need a plugin if you have FFI:
dup: srcfd <cdecl: long 'dup' (long) module: 'libc'> ^ self externalCallFailed
dup: srcfd to: dstfd <cdecl: long 'dup2' (long long) module: 'libc'> ^ self externalCallFailed
richie