maybe_chdir = cwd(rw_dir) if chdir_to_repo else contextlib.nullcontext()

repo = Repo.init(rw_dir)

# We need an impostor shell that works on Windows and that can be distinguished

# from the real bash.exe. But even if the real bash.exe is absent or unusable,

# we should verify that the impostor is not run. So the impostor needs a clear

# side effect (unlike in TestGit.test_it_executes_git_not_from_cwd). Popen on

# Windows uses CreateProcessW, which disregards PATHEXT; the impostor may need

# to be a binary executable to ensure the vulnerability is found if present. No

# compiler need exist, shipping a binary in the test suite may target the wrong

# architecture, and generating one in a bespoke way may cause virus scanners to

# give a false positive. So we use a Bash/Python polyglot for the hook and use

# the Python interpreter itself as the bash.exe impostor. But an interpreter

# We need an impostor shell that works on Windows and that the test can

# distinguish from the real bash.exe. But even if the real bash.exe is absent or

# unusable, we should verify the impostor is not run. So the impostor needs a

# clear side effect (unlike in TestGit.test_it_executes_git_not_from_cwd). Popen

# on Windows uses CreateProcessW, which disregards PATHEXT; the impostor may

# need to be a binary executable to ensure the vulnerability is found if

# present. No compiler need exist, shipping a binary in the test suite may

# target the wrong architecture, and generating one in a bespoke way may trigger

# false positive virus scans. So we use a Bash/Python polyglot for the hook and

# use the Python interpreter itself as the bash.exe impostor. But an interpreter

# from a venv may not run when copied outside of it, and a global interpreter

# won't run when copied to a different location if it was installed from the

# Microsoft Store. So we make a new venv in rw_dir and use its interpreter.