[agent] Found by the scheduled pip / requirements.txt bug-hunt routine (ledger #309).

Summary

For a pip project, socket-patch setup appends the line socket-patch[hook] to requirements.txt (HOOK_DEP, crates/socket-patch-core/src/setup/pypi/detect.rs:14). The hook extra on socket-patch 4.0.0 requires socket-patch-hook (Requires-Dist: socket-patch-hook; extra == "hook", scripts/build-pypi-wheels.py:197). But socket-patch-hook doesn't exist on PyPI: https://pypi.org/pypi/socket-patch-hook/json and /simple/socket-patch-hook/ both return 404, and .github/workflows/publish-pypi.yml has never run.

pip therefore can't satisfy socket-patch 4.0.0's [hook] extra. It backtracks to socket-patch 3.3.0, which has no hook extra, prints a WARNING, and reports success. No startup .pth is installed, so the committed .socket/ patches are never re-applied after a reinstall, even though setup reported status: success, updated: 1.

Impact

• The whole agent-mode + setup flow for pip (README "Python (pip / uv / poetry / pdm / hatch)": "Installing it lays down a startup .pth … that re-applies your committed .socket/ patches") silently doesn't work. After pip install --force-reinstall or a fresh venv, the package stays unpatched.
• As a side effect, it downgrades the user's socket-patch CLI to 3.3.0, which predates hosted and vendored modes.
• Any other installer that resolves socket-patch[hook] from PyPI is presumably affected the same way (uv, Poetry, PDM, Hatch). I only verified pip, so the other routines may want to confirm.

Repro

python -m venv v
v/bin/pip install --no-cache-dir "socket-patch[hook]==4.0.0"
# ERROR: Could not find a version that satisfies the requirement socket-patch-hook; extra == "hook" (from socket-patch[hook]) (from versions: none)
v/bin/pip install --no-cache-dir "socket-patch[hook]"          # the exact line `setup` writes
# WARNING: socket-patch 3.3.0 does not provide the extra 'hook'
# Successfully installed socket-patch-3.3.0
v/bin/python -c "import sysconfig,os;sp=sysconfig.get_paths()['purelib'];print([f for f in os.listdir(sp) if f.endswith('.pth')])"
# []  (no socket-patch hook .pth)

End to end on main f6b7fb9 (Linux, pip 24.0): socket-patch setup --yes → requirements.txt gains socket-patch[hook] → pip install -r requirements.txt installs socket-patch 3.3.0 → socket-patch scan --mode agent patches six → pip install --force-reinstall six==1.16.0 → six stays UNPATCHED on every later interpreter start. Reproduced twice.

Expected vs actual

• Expected (README setup, PyPI bullet): installing the dependency setup adds lays down the socket-patch-hook startup .pth, which re-applies patches. At the very least, setup or setup --check shouldn't report success for a dependency that can't be installed.
• Actual: the hook distribution can't be installed from PyPI, pip quietly falls back to 3.3.0 with no hook, and setup reports success.

OS × version

Probe run https://github.com/SocketDev/socket-patch/actions/runs/36772070619:

First bad release

4.0.0 is the first release whose setup targets requirements.txt (3.3.0's setup is npm-only), and it is also the first whose metadata names the missing socket-patch-hook. Note: release/v5-prerelease removes setup (#279) and the PyPI distributions (#298), but main and the latest release still ship this path.

Suspect location

• Release pipeline: .github/workflows/publish-pypi.yml:161 ("Publish socket-patch-hook to PyPI"). The workflow has no runs, and the project doesn't exist on PyPI (it needs its own trusted publisher, per the comment at :147).
• crates/socket-patch-core/src/setup/pypi/edit.rs:143 (requirements_add): writes an unpinned socket-patch[hook], which lets pip resolve it to a release with no hook extra instead of failing loudly. Pinning to the running CLI version (socket-patch[hook]==4.0.0) would at least turn this into a visible install error.