A stub that prints nothing makes `size=$(du -sk x)` empty, so every
`((size > 0))` is false and the trace walks past every guarded branch.
Two such traces compare identical while exercising none of the changed
code -- a green check that proves nothing, which is the exact failure
mode this harness exists to prevent.
--stub now takes `name=output`. Measured on a fixture whose `sudo rm -rf`
is guarded by a size test: the silent stub gives `size=[]` / "branch
skipped" and never records the rm; `--stub 'du=4096\t/some/dir'` gives
`size=[4096]` / "BRANCH TAKEN" and captures it.
This weakens the earlier disk_cleanup_check.sh trace, which used a silent
du stub: that trace only proved the empty-size path identical. The real
run from /tmp is what covered the populated path. Noted in the evidence.
Docs also record two limits found while surveying: file-placement
installers are not yet traceable (stub cp/chmod/ln and the trace is
empty; don't and it rewrites the live system), and baselines for scripts
reading relative paths must run from the script's own directory.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
fresh-install/main.sh calls git clone against live AUR URLs, makepkg, and
curl -- none of which belong in the default stub set, since plenty of
scripts read git state harmlessly and a blanket git stub would change what
they see rather than protect anything.
--stub git,curl,makepkg shadows them for one run. Verified: both calls are
captured in the trace with no repo cloned and no network hit, and the two
regression fixtures still behave (exit 1 for the set -e tail, four
circular-name-reference warnings for the nameref).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
verify_shell_split.sh sources the libs and never calls them, which is why
analyze_repo.sh shipped broken after passing every static check. This runs
the script for real with ~30 mutating binaries (sudo, pacman, systemctl,
adb, nft, mount, reboot...) shadowed by PATH stubs that record their calls
and exit 0, then prints a diffable trace: exit status, stubbed calls in
order, stdout, stderr.
Verified against both bugs the handoff documents: it catches the `set -e`
function-tail abort (exit 1, later calls absent from the trace) and the
self-referencing nameref (exit 0, correct stdout, `circular name
reference` in stderr). `systemctl is-active foo` stayed inactive across
all three runs, so nothing reached the live system.
This is what lets Decision 6 ("never execute an enforcement script") and
the user's "run-and-diff always" coexist. Handoff updated with both, plus
the win32_window.cpp resolution: it is tracked and listed in
CMakeLists.txt, so gitignore cannot work -- the exemption belongs in
~/utils/file_length/config.py.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
