Support paths with spaces in launchers

[konstin]

See #1997 (comment)

When creating a new launcher, we insert the path to the python interpreter as shebang. This fails if there is a space in the path:

#!/Users/ferris/my python project/.venv/bin/python
# -*- coding: utf-8 -*-
import re
import sys
from launchable import main
if __name__ == "__main__":
    sys.argv[0] = re.sub(r"(-script\.pyw|\.exe)?$", "", sys.argv[0])
    sys.exit(main())

The system tries to execute this as /Users/ferris/my with arguments python and project/venv/bin/python. We should instead use the same workaround as pip when there's a space in the path:

#!/bin/sh
'''exec' "/Users/ferris/my python project/.venv/bin/python" "$0" "$@"
' '''
# -*- coding: utf-8 -*-
import re
import sys
from launchable import main
if __name__ == "__main__":
    sys.argv[0] = re.sub(r"(-script\.pyw|\.exe)?$", "", sys.argv[0])
    sys.exit(main())

pip reference code: https://github.com/pypa/pip/blob/0ad4c94be74cc24874c6feb5bb3c2152c398a18e/src/pip/_vendor/distlib/scripts.py#L136-L165

[charliermarsh]

I can grab this one later if no one gets to it.

[pradyunsg]

FYI: https://github.com/pradyunsg/installer/blob/d01624e5f20963f046e67d58f5319e21a07aa03e/src/installer/scripts.py#L54

[charliermarsh]

Nice, thank you.