I think a comment I made here got lost... This "#if" is converting the UTF-8 encoding of argv[0] into a native string. Thus this code should be:
```
#if defined(_MAC_DESKTOP)
  /* UNCHECKED */ MCStringCreateWithBytes(argv[0], strlen(argv[0]), kMCStringEncodingUTF8, MCcmd);
#endif
```
Here we just create an MCStringRef direct from the UTF-8 encoded sequence of bytes.