## Summary
This is based on Pradyun's installer branch
(https://github.com/pradyunsg/installer/blob/d01624e5f20963f046e67d58f5319e21a07aa03e/src/installer/scripts.py#L54),
which is itself based on pip
(https://github.com/pypa/pip/blob/0ad4c94be74cc24874c6feb5bb3c2152c398a18e/src/pip/_vendor/distlib/scripts.py#L136).
The gist of it is: on Posix platforms, if a path contains a space (or is
too long), we wrap the shebang in a `/bin/sh` invocation.
Closes https://github.com/astral-sh/uv/issues/2076.
## Test Plan
```
❯ cargo run venv "foo"
Finished dev [unoptimized + debuginfo] target(s) in 0.14s
Running `target/debug/uv venv foo`
Using Python 3.12.0 interpreter at: /Users/crmarsh/.local/share/rtx/installs/python/3.12.0/bin/python3
Creating virtualenv at: foo
Activate with: source foo/bin/activate
❯ source "foo bar/bin/activate"
❯ which black
black not found
❯ cargo run pip install black
Resolved 6 packages in 177ms
Installed 6 packages in 17ms
+ black==24.2.0
+ click==8.1.7
+ mypy-extensions==1.0.0
+ packaging==23.2
+ pathspec==0.12.1
+ platformdirs==4.2.0
❯ which black
/Users/crmarsh/workspace/uv/foo bar/bin/black
❯ black
Usage: black [OPTIONS] SRC ...
One of 'SRC' or 'code' is required.
❯ cat "foo bar/bin/black"
#!/bin/sh
'''exec' '/Users/crmarsh/workspace/uv/foo bar/bin/python' "$0" "$@"
' '''
# -*- coding: utf-8 -*-
import re
import sys
from black import patched_main
if __name__ == "__main__":
sys.argv[0] = re.sub(r"(-script\.pyw|\.exe)?$", "", sys.argv[0])
sys.exit(patched_main())
```
Charlie Marsh
e811070ef1