Codex re-fires SessionStart with source "compact" after every context
compaction; the summary keeps progress but sheds the bootstrap and any
active skill's instructions — measured July cause of post-compaction
dispatch drift in long SDD runs (with re-injection: 18/18 hook fires,
66/66 post-compaction dispatch tuples correct in a 12.4h stress run).
Codex discovers skills natively at startup, so the hook is silent
there: the compact re-fire is the one unowned lifecycle point.
Adds the plugin-provided hook (hooks-codex.json + session-start-codex,
compact-only, fails open), wires it into the manifest and package,
documents install/trust behavior, updates codex-tools.md with the
re-grounding fallback, and tests the hook lifecycle, manifest, and
archive contents.
Rebuilt from the July codex-spinout-fixes branch, pared to the hook
core: the dispatch-hints layer it used to ride with is superseded by
the merged 2059-2062/2077-2080 stack and is dropped.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The packaging pipeline only worked on a Mac with default umask, for
three stacked reasons:
- The deterministic-metadata tar flags (--uid/--gid/--uname/--gname)
are bsdtar spellings; GNU tar rejects them, so the tar.gz archive
step died on Linux. Detect the tar flavor and use --owner=:0
--group=:0 --numeric-owner on GNU tar, which writes byte-identical
ustar headers (uid/gid 0, empty uname/gname).
- Staged file modes depended on two umasks canceling out: git archive
masks entry modes with tar.umask (git default 0002 -> 775), and the
unflagged tar extraction re-masked with the process umask (022 on
macOS -> 755, but 002 elsewhere -> 775). Pin tar.umask=0022 on the
archive call and extract with -p so staged modes are canonical
755/644 on every machine.
- The test's timestamp assertion parsed bsdtar's -tv column layout and
expected epoch 0 rendered in a US timezone ("Dec 31 1969"); GNU tar
uses different columns and UTC hosts render "1970-01-01". Assert
mtime == 0 via python3 tarfile instead, matching how the test
already checks zip timestamps.
tests/codex/test-package-codex-plugin.sh now passes on Linux/GNU tar;
the bsdtar branch preserves the exact flags that passed on macOS.
