Review found the byte-versus-character witness asserting something
adjacent to its contract. It set `LC_ALL=C.UTF-8` and assumed the
locale took effect. Locale names beyond `C` and `POSIX` are
implementation-defined, so where that one is absent the shell falls
back to byte semantics --- and then the character-counting mutant
counts bytes too, agrees with the fix, and the row passes while
proving nothing. M-G-6 was killable here and unkillable elsewhere,
which is the same as not having it.
The locale is now chosen by BEHAVIOUR. Candidates come from `locale -a`
so the set reflects what is installed, and each is probed through the
same `/bin/sh` the gate runs under, asking `${#x}` on a two-byte
character and requiring `1`. No qualifying locale is a loud panic
naming what was tried, never a skip: a skip would be indistinguishable
from a pass, which is the failure mode this replaces.
M-G-8 proves the fix in three legs, because the hazard lives in the
environment rather than the code:
8a mutant gate, probed locale -> the row fails, and the
exact-boundary row still passes
8b SAME mutant gate, locale forced to `C` -> the row passes.
The defect reproduced rather than argued.
8c no candidate can qualify -> panic naming the candidates
Also marks framing revision 6 approved and records M-G-8 in the ledger.
Gates: all nine green under `env -u TMPDIR`, log 20260813T182020Z.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
Every item here is the same failure in a different place: a property
fixed or claimed, and a suite that would stay green without it.
**CANONICAL ANCESTRY WAS UNWITNESSED.** Round 3 fixed word-splitting
and lexical traversal and verified both BY HAND, which is exactly the
evidence that does not survive the next edit --- reverting to the
`for _anc in $(... dirname ...)` loop left all 26 rows green. There is
now a row driving a **space-containing root** (an unquoted expansion
tears it into fragments and the real ancestor is never tested, so the
guard passes on the path it must reject) and a **symlinked root** (a
marker visible only after `pwd -P`, which is what `detect_project`
sees). `M-G-8` restores the old loop and fails it. The traversal is
encoded in framing §2a rather than left as an implementation detail.
**THE SOCKET GUARD MISSED ITS OWN BOUNDARY.** The rows generated ~51-
and ~71-byte paths against a 55-byte cutoff, so they constrained the
guard's EXISTENCE and not its VALUE: raising the budget from 103 to 118
would have kept both green. They now hit **exactly 55 accepted and 56
rejected**, assert the measured byte lengths, and check that the
refusal reports precisely one byte over.
**REJECTION-CLEANUP CHECKED ONE AREA OF TWO.** Only `<root>/tmp` was
inspected, so leaking AMBIENT alone would have passed --- and AMBIENT
is created before the guard can measure anything, which is the whole
reason the trap moved earlier. Both areas are inspected now, the
ambient one under the derived per-worktree target whose hashed name the
test does not compute.
**THE MULTIBYTE ROW DEPENDED ON THE INHERITED LOCALE.** Under
`LC_ALL=C`, `${#var}` already counts bytes, so the character-counting
mutant passed and the row's verdict was a property of the environment
rather than of the code. It sets `LC_ALL=C.UTF-8` explicitly;
`M-G-6` now fails even when the harness itself runs under `LC_ALL=C`.
Stale test prose corrected, including one claim that was the very
inference the ancestor check exists to refute: **placement under a
managed root does not make a path marker-free**. Also, the tmp parent
is SHARED between worktrees and untouched by `--prune` (unlike the
ambient root, which is per-worktree), and the module header named
framing revision 4.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
**THE ANCESTOR WALK WAS WRONG TWICE OVER.** `for _anc in $(...)`
word-splits on IFS, so a gate root containing a SPACE was torn into
fragments and the real ancestor never tested --- the check passed on
exactly the path it should reject. And `dirname` walks LEXICAL
ancestry while `detect_project` canonicalizes, so a symlinked root hid
a marker the editor plainly sees. The walk resolves with `pwd -P` first
and iterates a quoted `while`; both shapes are verified by hand
(space-containing root refused, symlinked root refused at its real
path).
**THE 103-BYTE GUARD HAD NO WITNESS AT ALL** --- every other row runs
with a short root, so the guard is silent and a broken one looked
identical. Three rows now aim at it deliberately: boundary rejection
and acceptance, a MULTIBYTE root (each `é` is one character and two
bytes, so it is rejected only if the guard measures bytes), and
**rejection must reap both created areas**, which is the leak the early
trap exists to prevent.
**The `Cargo.toml`-DIRECTORY case was claimed and not covered**, and
the consequence is exactly as review predicted: reverting only the
language-marker arm to `[ -e ]` stayed green. The marker-type row now
drives all three shapes, and `M-G-5` --- that precise revert --- fails
it.
**Prose brought level with the implementation.** The framing, the
handoff and the ledger all said 108; the supported floor is **103
usable bytes**, Darwin's 104-byte array minus its NUL. The ledger also
still said `<pid>`, the superseded 21/30 reserve, and `M-G-1`.
**And the ruling said nested gates "do not pay" the reserve, which is
false and would have licensed exempting them.** They pay it in full;
the short layout merely gives them the headroom to satisfy an unchanged
production guard. Reworded, because the wrong version is the one a
future reader would act on.
**THE btrfs CAUSAL CLAIM IS WITHDRAWN.** The draft argued that a
one-second deadline plus a slower filesystem was a plausible new
mechanism for the fourth `managed_retry` occurrence. It does not
survive inspection: the deadline bounds the connection RETRY loop, not
the socketpair handshake that returned `BrokenPipe`, and the filesystem
work happens before it is armed --- the tempdir is created and never
bound. The environmental change is still recorded, as a CHANGE rather
than a mechanism, so a later occurrence can compare like with like.
Recording a mechanism the code does not support is worse than
recording none: the next occurrence gets measured against a story
instead of the evidence. TMPDIR stays disk-backed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
**108 IS LINUX'S NUMBER, NOT THE FLOOR.** Darwin's `sun_path` is 104
(xnu `bsd/sys/un.h`) and pmacs supports macOS --- CI runs a
`macos-latest` leg --- so a Linux-derived limit passes on the machine
that writes it and bind-fails on the other. **The usable PATH length is
one less than the array**, because the stored value is NUL-terminated:
103 on Darwin, 107 on Linux. The script takes **103**, and the
diagnostic says which platform's floor it is quoting.
**THE NESTED CASE IS NOW RULED, NOT ACCOMMODATED BY LOOSENING THE
GUARD.** The reserve exists for fixtures that bind sockets under
TMPDIR; this script's own behaviour suite runs nested gates whose plans
are synthetic and bind nothing, so charging them the fixture reserve
rejects a configuration that cannot suffer the failure it guards
against. Exempting nested runs was rejected --- it makes the guard
untestable in the very configuration the tests exercise, and "this run
is nested" is not reliably knowable. **The suite roots its gates at a
short base instead**, so a nested TMPDIR is ~24 bytes rather than ~71
and clears the real reserve. Recorded in revision 6 with the rejected
alternative, and with the obligation that a future row which DOES bind
a socket must move off that base and take the reserve with it.
**MIRRORING THE MARKER NAMES WAS NOT ENOUGH; THE TYPES ARE PART OF THE
CONTRACT.** `match_marker` requires `.git` to be a DIRECTORY and the
seven language markers to be FILES, so `[ -e ]` rejected ancestors
project detection walks straight past. The case is not exotic: **a git
WORKTREE has a `.git` FILE**, so every worktree in this repository
would have tripped the guard. It tests `[ -d ]` for `.git` and `[ -f ]`
for the rest, with a witness covering all three shapes --- `.git` file
accepted, `.git` directory refused, `Cargo.toml` directory accepted.
That witness keys on WHICH marker the gate named rather than on whether
a refusal happened, because the ancestors of any base a test can create
are outside its control; "no refusal" is not a claim it can make
anywhere, while "the refusal did not name MY file" is. `M-G-4` reverts
the guard to existence-only and the row fails.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
**THE PROPAGATION WITNESS DID NOT OBSERVE INHERITANCE.** The runner's
`eval` expanded `$TMPDIR` in the PARENT before `sh -c` ever started, so
the child received an already-substituted literal --- and an unexported
`TMPDIR=` would have passed the row unchanged. Single-quoted inside
`sh -c` now, so the CHILD expands it. **M-G-1b keeps the assignment and
removes only `export`: the row fails.** That is the mutation the
previous version could not catch, and the reason to prefer it over
M-G-1's blunter deletion.
**THE RESERVE WAS NOT THE MAXIMUM.**
`/.tmpXXXXXX/directory-target.sock` is 33 bytes
(`tests/gpu_invocation_acceptance.rs`), so paths of 76-78 passed the
30-byte guard and still blew the 108-byte limit during the CRDT sweep.
Reserve is 48 now --- the measured maximum plus ~45% headroom. And the
length is counted in BYTES: `${#var}` counts CHARACTERS under a UTF-8
locale while `sun_path` is byte-limited, so a multibyte path measured
short and passed a check it should fail.
**A MANAGED ROOT IS NOT INHERENTLY MARKER-FREE**, and assuming it was
rebuilt the original defect one directory up: a `.git` in `$HOME`, a
marker above `$HOME/build`, or a contaminated
`PMACS_GATE_TARGET_ROOT`. Placement under a directory the gate owns is
NECESSARY, NOT SUFFICIENT, and the old test proved only placement. The
gate now walks the ancestors and refuses, naming the marker it found.
`PMACS_GATE_ALLOW_ANCESTOR_MARKER` is the documented test-only escape,
beside `PMACS_GATE_TARGET_ROOT` in kind and risk: the behaviour tests
run under a tempdir whose ancestors they do not control, on a machine
whose `/tmp` carries this very marker, and their plans are synthetic so
no markerless fixture exists to re-root. **The check is witnessed by a
row that deliberately does not set it**, and M-G-3 (check removed)
fails that row.
**The guard leaked what it exists to manage.** It created both
temporary areas and exited before the trap was armed, so every
rejection left an AMBIENT and a TMPDIR behind. The trap is installed
first now; verified by rejecting a run and finding neither.
**`tmp/$$` with `mkdir -p` was not fresh.** PIDs are reused, so after a
SIGKILL it silently ADOPTS a leftover directory and the run inherits
another run's fixtures. `mktemp -d` fails rather than reuses.
**Prose corrected to match.** The handoff described
`<target>/gate-tmp/<stamp>-<pid>`; the implementation uses
`<gate-root>/tmp/<mktemp>`. Comments called the shared parent
per-worktree and pruned --- it is neither: `--prune` only considers
directories carrying an ownership marker, so the parent is skipped and
each run removes its own leaf.
**AND THE LANE CLAIMED A FRAMING EXCEPTION THAT DOES NOT EXIST.**
`AGENTS.md` says framing -> approval -> branch -> implement,
unconditionally; "the fix was already recorded as standing" is not an
exemption it grants. `docs/gate-script-framing.md` is amended as
**revision 6, AWAITING APPROVAL** --- a widening of §2's existing
isolation responsibility rather than a new feature, which is why it
amends that document instead of opening another. **This PR must not
merge before that revision is approved.**
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
* build: scripts/gate — a target dir per worktree, and one gate suite
Parallel worktrees do not work on this machine, and the reason is one
exported variable: every checkout builds into one CARGO_TARGET_DIR, and
cargo takes an EXCLUSIVE LOCK on it. Two lanes building at once do not
run in parallel — the second blocks — and they invalidate each other's
artifacts, so alternating between them recompiles from scratch. Parallel
development under that arrangement is slower than serial.
MEASURED, BECAUSE THE FIRST PLAN WAS WRONG. The shared directory is
285G, which drove a proposal to add sccache so per-worktree directories
would not lose artifact sharing. That number is years of accumulation
across TWO projects (pmacs and levcs share it). Measured directly: a
cold `cargo test --workspace --no-run` is 80s and 19G. And sccache
across two target directories hits 50% on C/C++ and **0.00% on Rust** —
rlibs embed their target-dir path, so dependency artifacts are not
bit-identical between directories and `--extern` hashes cascade into
misses. There is no sharing worth buying back. sccache stays configured
and earns its keep on C/C++; it is not what makes parallel lanes work.
The script also owns the FIXED gates, because a procedure living only in
prose gets executed differently each time — twice in the session that
motivated this:
- a sweep run with `--tests` instead of `--workspace`, silently
dropping pmacs_protocol and pmacs_gpu, including protocol tests that
same lane had just written;
- a sweep piped through `grep` before anyone read it, so an
intermittent red could not be matched against ci-red-signatures —
a row needs its fragments. That is registry note U2, and then U3
when it happened AGAIN.
Hence durable per-gate logs with the sweep paths printed. The remedy is
real: this lane's own run diagnosed its failures from the log without
re-running anything.
WHAT THE SCRIPT IS NOT AUTHORITATIVE FOR. Handoff §3 keeps policy and
keeps CHOOSING the touched acceptance suites, which arrive only via
`--acceptance`. No script can infer those from a working tree, and one
that guessed would report coverage it does not have.
THREE HAZARDS SPECIFIED RATHER THAN LEFT TO CHANCE:
- `cmd | tee log` reports TEE's status, so a failing gate would exit 0
and the suite would read green. `pipefail` is not POSIX.
- `cmd > log; rc=$?` never reaches the assignment under `set -eu`
(which scripts/bite already uses) — the shell exits at the failing
command, so nothing prints which gate failed or where its log is,
destroying the point of capturing it. The runner is therefore an
`if` condition, the only `set -e` exemption.
- CARGO_TARGET_DIR (env) OVERRIDES build.target-dir in config.toml, so
a per-worktree config file silently does nothing. Only a
per-invocation value beats it.
Pruning is dry-run by default, `--force` to delete, and refuses any
directory without a `.pmacs-gate-target` marker. "Live" means a git
worktree record carrying NO `prunable` line — git keeps listing a
worktree whose directory was deleted without `git worktree remove`, and
treating listed as live would make exactly the reclaimable directories
permanently ineligible.
ONE HONEST FINDING FROM MUTATION TESTING. Three mutations came back
vacuous, and all three are redundant defences rather than test holes:
git already returns resolved physical paths from both
`rev-parse --show-toplevel` and `worktree list --porcelain`, so canon()
is belt-and-braces; and the prune path guards the marker twice. Recorded
in the script and the tests so a later reader does not mistake a
"vacuous" result for a gap — or delete a defence because a test did not
notice.
VERIFICATION. 11 acceptance tests over the no-gates paths (running the
script for real inside the suite would recurse), each pointed at a
tempdir via PMACS_GATE_TARGET_ROOT so the real managed root is
unreachable — a prune bug is unrecoverable. Mutation-tested: `--tests`
in the sweep, an unconditional CRDT sweep, and pruning on a dry run all
fail their intended test.
Observed in a real run, which is how the framing said to confirm the
parts a test cannot: the failed-gate names and log paths print, the
ambient directory is created and reaped by the exit trap, and every log
appears. The run exits non-zero because of R8 — the pre-existing,
merge-base-confirmed listview failure — which means `scripts/gate`
cannot go green on this machine until R8 is diagnosed. That is a
property of the tree, not of this change.
Framing: docs/gate-script-framing.md (revision 4, approved).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
* fix(gate): two ways the script could do harm, and four smaller defects
Review round 1 on #225. Neither blocking finding was a design gap ---
both were the implementation failing to honour its own framing, which
is the case a framing document cannot prevent by itself.
PRUNE COULD DELETE EVERY MANAGED DIRECTORY. §2.6 requires the live
worktree set to be ESTABLISHED. The code piped `git worktree list`
straight into awk and the caller masked the result with `|| true`, so
running from outside any repository produced an EMPTY live set --- and
an empty live set means "every managed directory is an orphan", so
`--prune --force` would have deleted all of them, live lanes' artifacts
included. The failure mode was silent and total.
Two refusals now, and they are deliberately redundant: not inside a
worktree, and the enumeration itself failing. `live_worktrees` captures
git's output and returns non-zero rather than emitting nothing, so
"I cannot tell what is live" is unrepresentable as "nothing is live".
An empty porcelain listing counts as failure too --- a repository always
has at least its own worktree.
--ACCEPTANCE WAS SHELL-INJECTABLE. The name is interpolated into a
command the runner evaluates, and nothing validated it, so
`--acceptance 'x; rm -rf ~'` would have run. Now an allowlist of what a
cargo test target can actually be named --- letters, digits, underscore,
hyphen --- refused at parse time, before any gate. Rejection rather than
escaping: there is no legitimate suite name that needs quoting.
FOUR SMALLER ONES:
- Log directories carried a whole-second timestamp, so two runs in the
same worktree within one second shared one and could overwrite each
other's evidence --- reintroducing U2/U3 through a naming choice.
The PID is now part of the name.
- The ownership marker is DOCUMENTED as one line, so it is enforced as
one line instead of read head-first. Acting on the first line of a
file we did not understand is how a corrupted marker authorises a
deletion.
- The `prunable` test returned green when `git worktree add` failed,
so the only coverage of that rule could silently never run. It now
fails loudly.
- Its cleanup ran after the assertions, so a panicking assertion would
have left the real repository carrying a stale worktree record. Now
a `Drop` guard.
MUTATION TESTING, HONESTLY REPORTED. The injection and marker fixes bite
individually. The two prune guards do NOT --- each alone satisfies the
outside-repo test, so mutating one at a time reads as vacuous. Removing
BOTH fails the test, which is what establishes that the test detects the
unsafe state rather than being blind to it. Recorded in the test so a
later reader does not delete one guard on the grounds that nothing
noticed.
ALSO: handoff §3's ambient-root caveat still said "until the
ambient-root isolation lane lands". #206 merged; the five variables are
now belt-and-braces for external and integration paths, and `scripts/gate`
sets them regardless.
R8 PROMOTED. `docs/ci-red-signatures.md` gains the reason it stops being
a catalogued curiosity: with the gate suite reduced to one command, R8
makes that command exit non-zero on a clean tree EVERY TIME, and a gate
that is always red is a gate nobody reads. `docs/active-work.md` gains a
lane. It is still not a regression from #223 or #225 --- the merge-base
control says so --- and the lane's first job is diagnosis, because a
change that made the assertion pass without explaining the prefix strip
would convert a visible failure into an invisible one.
15 acceptance tests. Observed run re-confirmed: failed gates named with
log paths, ambient directory created and reaped, distinct log directory,
exit 1 from R8 alone.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
* docs: the #225 lane, and R8 diagnosed to a stray /tmp/.git
TWO LEDGER GAPS, both found by review.
and — the part that matters — an explicit GATE STATUS: NOT GREEN
section. `scripts/gate` exits 1 on this branch and on a clean `main`
because R8 fails m4_acceptance and therefore the sweep. That is a merge
blocker under the standing rule, and #225 is the worst possible lane to
grant a silent exception to: it is the lane that makes the gate suite
authoritative, and a tool shipping with its own gate red teaches the
opposite of what it exists to teach.
The lane also records that it was written after the PR existed, again,
because review asked again. Two lanes in a row now. The correction from
only evidence of that.
R8 DIAGNOSED, and the `TMPDIR` hypothesis was right:
1. `display_path` (builtin/runtime/lsp.lua:2397) shortens a location
against the DETECTED PROJECT ROOT before rendering it.
2. `project.detect` walks UPWARD for a marker; from
/tmp/.tmpXXXX/r.rs it reaches /tmp.
3. This machine has a stray `/tmp/.git` — an EMPTY DIRECTORY, not a
repository. The `.git` marker is directory-only, so an empty
directory still matches.
4. Root resolves to /tmp, the prefix is stripped, and the rendered row
is exactly the observed `.tmpXXXXXX/r.rs:12:3`.
Controlled, not inferred: the same test with TMPDIR outside /tmp PASSES.
THE CODEBASE ANTICIPATED THIS BY NAME. src/project.rs:208 documents
`detect_project_within(start, markers, stop_root)` as existing "so a
stray marker in a temp-dir's ancestor (e.g. a developer's /tmp/.git)
can't leak into a fixture that lives below it." The mechanism exists;
this fixture does not use it.
So the row splits, and the halves need different fixes. The failure is
ENVIRONMENTAL — nothing about pmacs is wrong when a real project root
sits above a file, that is the feature, and removing /tmp/.git makes the
gate green immediately. The fixture being ENVIRONMENT-DEPENDENT is a
real defect, and bounding its detection is what retires the row.
PROVENANCE UNRESOLVED, and I am not going to assume in my own favour:
/tmp/.git is dated 2026-08-07 23:17, inside this session's window, and
may have been created by this session's own work — a stray git
invocation from /tmp would do it. The earlier merge-base control stays
valid as "this tree has it" but says nothing about WHEN the environment
acquired the marker, so "pre-existing" must not be read as
"long-standing".
Nothing deleted: /tmp/.git is outside the repository and I cannot
confirm I created it, so removing it is the user's call.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
* docs: rebase onto the R8 fix; scripts/gate now exits 0
#226 (`dcb852e`) retired R8 by bounding the LSP fixture's project
detection. This branch rebases onto it, and the thing that was blocked
is now demonstrable: **`scripts/gate` exits 0** --- all nine gates green
in one command, the first time the tool has passed the suite it exists
to run. That is #225's own acceptance criterion, and it could not even
be stated while the script did not exist on `main`.
REBASE RESOLUTION, per the standing rule that #226's R8 documentation is
authoritative. Every conflict was in R8 text this branch wrote while the
row was still an open investigation:
- two in `docs/ci-red-signatures.md`, both resolved to #226's retired
row with this branch's pre-fix copy dropped;
- the framing-doc pair --- e71e1bd added `docs/r8-fixture-boundary-
framing.md`, 7cfba73 removed it --- both SKIPPED. They are net-zero
here and `main` owns that file authoritatively; replaying the second
would have deleted `main`'s copy, which is the one failure mode a
mechanical "resolve each conflict in turn" would have walked into.
TWO STALE LANES REMOVED. This branch's "R8 --- NEEDS A LANE"
investigation block describes a diagnosis that has since happened and a
fix that has since landed. And #226's own lane arrived through the
rebase still saying "OPEN, HELD FOR REVIEW"; Rule 4 retires it now that
it has merged, its durable facts already being in the retired registry
row and the handoff section 6 census. Leaving either would have left the
ledger asserting that a merged fix was still an open investigation.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016bqGA6s9tTUFzYpbeW3tai
---------
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Levi Neuwirth