The Windows build of Python appears to be more strict when it comes to

Unicode vs. byte strings in certain cases. In particular, their

implementation of getpass() expects byte strings for the prompt, and

their subprocess.Popen expects an environment dictionary with byte

strings. Unicode strings, in these cases, cause exceptions to be raised.
We now mark these as byte strings, satisfying the Windows

implementation.

Had some Windows users try these changes. They verified they were able to

supply their credentials and post changes for review successfully.