Assuming that the `MOZILLABUILD` environment variable is set, allow
invoking Mach from non-MozillaBuild terminals.
Note that MozillaBuild still needs to be installed, and the
`MOZILLABUILD` environment variable will have to be set.
For future reference: when I tried setting this up with Windows
Store's Python 3.9, I encountered issues when running binaries installed
via `pip`: it would fail with `abort: failed to load Python DLL
python3x.dll`.
Differential Revision: https://phabricator.services.mozilla.com/D133936
This allows running mach on PowerShell for better Windows build experience. It currently has a limitation that blocks any whitespace use but such use should be rare enough.
Differential Revision: https://phabricator.services.mozilla.com/D101673
Mitchell Hentges
Kagami Sascha Rosylight