This directory being empty is the healthy steady state. A fragment appearing in a diff is the alarm; a fragment sitting here on next is spent cruft. README.md is not a fragment — every reader filters on .json — and exists so the directory (which CONTEXT.md and CONTRIBUTING.md both reference by path) survives the sweep that empties it.

The lifecycle, in three steps

The gate names its own remedy. When an emitted-artifact hash moves, or a gsd-core/workflows/*.md / agents/gsd-*.md file grows, and your diff cannot explain it, the failure output tells you which key to use and prints a minimal valid document to paste. Create a NEW fragment named for your issue or PR (<NNNN>-<slug>.json) — never reuse someone else's, and never revive the legacy single tests/emitted-drift-ack.json.
Note the two key spaces. The message says which one applies. An unattributable hash ripple is keyed on the emitted path (skills/gsd-add-tests/SKILL.md); growth is keyed on the bare filename as it appears under gsd-core/workflows/ or agents/ (explore.md).
The fragment is deleted once it has merged (#3078). Every entry is scoped to the diff that introduced it, so the moment it lands on next its prose is already at the base — it is spent and can no longer clear anything, while still owning its path keys. The guard-no-ack-on-next job reds next and prints the exact git rm for every fully-spent fragment.

You no longer have to run that git rm yourself (#3875). The ack-fragment-sweep workflow runs every six hours, asks the guard for its own sweep list (--sweep-plan), and opens a PR deleting exactly what the guard named. Deleting the fragment in a follow-up PR by hand still works and is still welcome — it is simply no longer the only thing standing between a merged fragment and a red next.

The sweep is automated because the manual remedy could not keep up. The guard evaluates at MERGE time; a hand-authored git rm is fixed at BRANCH time, so any ack-carrying PR that merges in between invalidates it. #3823 lost exactly that race to #3809 on its own merge commit and left next red for 24 consecutive pushes.

Why the sweep exists

Fragments end the file conflict the single shared document caused. They do not end the key conflict: two ack sources may never name the same path, and that is a hard, loudly-reported error. So a fully-spent fragment left here walls off every path it owns — the next PR to grow one of them can declare it neither in the owning fragment (spent, gates nothing) nor in its own (duplicate). #2914 assumed a persisting fragment was harmless; #3078 measured the cost at 45 fragments owning 403 paths and made the guard sweep them.

A partially spent fragment is deliberately left alone. That asymmetry is what keeps the re-arm route working: appending prose to a live entry re-arms it, and re-arming deliberately costs an actual new sentence — the comparison strips zero-width characters and collapses whitespace precisely so a zero-information edit cannot fake one.

Never pin a fragment in a test

A fragment is deleted the moment it has merged (see step 3 above), so any test that asserts one exists, or asserts its contents, will fail the instant guard-no-ack-on-next sweeps it — and that failure has nothing to do with the behavior the fragment once explained. This has already cost two suites: tests/emitted-attribution.test.cjs's three #2914 migration pins, and tests/agent-tracked-source-rule.test.cjs's #3645 growth-ack pin. What a test may legitimately assert is the BEHAVIOR the ack explains, or the guard's own verdict (assertNoAllSpentFragments, assertAbsentOnNext) — never the paperwork.

Do not regenerate anything

There is no baseline file to re-run a generator over; #2724 deleted it. If you find yourself hunting for one, that is the predictable wrong guess.

See CONTRIBUTING.md → "Editing shipped content", docs/TESTING-SUITES.md, and CONTEXT.md's RULESET.EMITTED_ATTRIBUTION for the full model.