test: two guards read the prose describing their subject as code

CHANGELOG.md

@@ -110,6 +110,51 @@ true until the next version shipped.
 
   NOT A REGRESSION FROM #1107: the old constant `0.5` also beat the base for this
   query and the planner also chose the projection. What changed is how confidently.
+- Two guards read the prose describing their subject as if it were the subject
+  (#1123). One of them reddened on a comment.
+
+  `selftest/320` counted `MAJOR_FAIL=` over `run_all_versions.sh`, which carries 874
+  comment lines, and expected zero. MEASURED: adding one comment saying the old
+  spelling was `MAJOR_FAIL=` before #967 renamed it, and changing no code, took
+  `harness_selftest` to `1080 passed + 1 failed`. The arm exists to keep that name
+  retired, so the sentence that records the retirement is exactly what breaks it.
+
+  `selftest/080` counted the bare word `grep` over `harness_selftest.sh`, a file of
+  61 comment lines about readers. It passes today only because that file happens to
+  contain the word zero times.
+
+  Both now strip comments into a variable and read the variable, with a herestring
+  rather than a pipe, which is the form part 080 itself requires (#486).
+
+  PROVED IN FOUR ARMS, because a guard that stops flagging prose looks identical to
+  one that stopped working:
+
+      clean tree                              1081 passed + 0 failed
+      the comment that reddened 320           1081 passed + 0 failed   (was 1080 + 1)
+      a comment mentioning `grep`             1081 passed + 0 failed
+      a REAL reader put back in the subject   1080 passed + 1 failed   <- still caught
+
+  THE COUNT I COULD NOT PRODUCE WHEN I FILED #1123, produced. The first attempt
+  extracted the surrounding `"$(grep ...` rather than the grep's own pattern and
+  reported 54 "exposed" including obviously immune cases, so nothing was published.
+  Parsing each `$(...)` body with `shlex` instead of regexing the line fixes it:
+
+      126 sweeps over shell source
+       34 anchored at ^, so a comment line cannot match
+       92 unanchored
+        2 unanchored AND over a commented file AND the pattern is a bare identifier
+
+  Both of those two were real and both are fixed here. The wider 92 is a
+  MEASUREMENT AND NOT A BUDGET: `/pbt/run\.sh$` is unanchored and cannot appear in
+  prose, and deciding which patterns plausibly can is a judgment a guard should not
+  pretend to make. `CONTEXT.md` carries the rule and the numbers; no gate is added
+  on the 92.
+
+  The justification in 080 also carried a stale count -- "60 lines, zero" for a file
+  that is now 90 lines. Corrected, with the growth noted, because the exposure
+  surface grew with it.
+
+  No check names change, so no ledger row moves and the census stays at 1391.
 
 - The union-merge page did not say why rebasing works where merging does not
   (#1116 follow-up).

CONTEXT.md

@@ -261,6 +261,55 @@ Python that reaches into shell:
   reported "one ledger row covers 2" -- and the right response to a name that already
   exists is to ask why, not to rename it. Anchor a check sweep at `^[[:space:]]*`.
 
+- **A sweep over shell source cannot tell code from the prose describing it.**
+  Anchoring is only half the decision. Four guards got this wrong in one week, in
+  both directions, and every one was silent (#1123).
+
+  ```
+  selftest/070 flagged its own subject's comment, which quoted the pattern it greps for
+  grep -l pgc_setup counted six comments saying "skipped deliberately" as CALLS
+  the same trap as an EXCLUSION dropped those six, and with them 233 records
+  a record-pattern matched the word `check` inside run_all_versions.sh's echo strings
+  ```
+
+  Over-inclusion reads as a strict guard; under-inclusion reads as a clean tree.
+  Neither announces itself.
+
+  **Three decisions, and the third removes the question where it applies:**
+
+  1. **Strip comments.** `grep -vE '^[[:space:]]*#'` into a variable, then read the
+     variable. A herestring, not a pipe -- part 080 forbids the pipe (#486).
+  2. **Decide whether string literals count, and say which.** A pattern that
+     matches inside an `echo` is a different sweep from one that does not, and
+     stripping comments does not settle it.
+  3. **Prefer a population that cannot contain prose about itself.** Sweeping the
+     REGISTERED SUITES rather than `test/*.sh` dropped `run_all_versions.sh` out of
+     scope, because the runner is not a suite. That fixed one of the four with no
+     pattern work at all.
+
+  **Measured over this tree**, with each grep's own pattern extracted by `shlex`
+  from the `$(...)` body rather than by a regex over the line -- which is the part
+  that was wrong the first time and produced a number too bad to publish:
+
+  ```
+  126 sweeps over shell source
+   34 anchored at ^, so a comment line cannot match
+   92 unanchored
+    2 unanchored AND over a commented file AND the pattern is a bare identifier
+  ```
+
+  That last class is the one that bites, and both instances were real. In
+  `selftest/320` the pattern was `MAJOR_FAIL=` over a runner carrying 874 comment
+  lines: adding one comment saying the old name was `MAJOR_FAIL=`, changing no
+  code, took `harness_selftest` to `1080 passed + 1 failed`. In `selftest/080` the
+  pattern was the bare word `grep` over a file of 61 comment lines about readers.
+  Both now read code only.
+
+  **The wider count is a measurement, not a budget.** "Unanchored" is not
+  "exposed": a pattern like `/pbt/run\.sh$` cannot plausibly appear in prose, and
+  whether one can is a judgment a guard should not pretend to make. The narrow
+  class above is the part worth checking by hand when a sweep is written.
+
 - **The one permitted cross-reference, named as the rule asks.**
   `test_the_two_fingerprint_implementations_cover_the_same_inputs` asserts that the
   shell path and the Python path give the same value, which is to say that neither

test/selftest/080-no-suite-pipes-a-captured-string.sh

@@ -301,15 +301,21 @@ _epipe_scanned="$(printf '%s' "$_epipe_files" | grep -c . || true)"
 # '"'"'/harness_selftest.sh:'"'"'` entered with the rule itself (23c96c7, 2026-08-07), when
 # harness_selftest.sh was the monolith and held 25 occurrences of `grep` inside its
 # own explanation of the forbidden shape. #554 split that file into the parts in
-# this directory three days later, and it has held none since: 60 lines, zero.
+# this directory three days later, and it has held none since: 90 lines, zero.
+# (60 when that sentence was written; the file has grown and the count with it,
+# which is why the arm below now reads code rather than the whole file.)
 #
 # What remains is the DERIVED exemption -- a line inside a quoted heredoc is text,
 # whatever file it sits in -- which is the form the comment above already argues
 # for. The arm below keeps the removal honest. Put a reader back into
 # harness_selftest.sh and the sweep will flag it, which it should: that file runs
 # its pipelines like any other.
+# CODE ONLY (#1123). The pattern here is the bare word `grep`, which is the single
+# most likely word to appear in a comment in a file about readers, and that file
+# carries 61 comment lines. Counting the prose would redden this arm for a sentence.
+_hs_code="$(grep -vE '^[[:space:]]*#' "$TESTDIR/harness_selftest.sh")"
 check "premise: the file the old filename exclusion named holds no reader to exclude" \
-	"$(grep -c 'grep' "$TESTDIR/harness_selftest.sh" || true)" "0"
+	"$(grep -c 'grep' <<<"$_hs_code" || true)" "0"
 
 check "and the scan examined the suites rather than finding nothing to read" \
 	"$([ "${_epipe_scanned:-0}" -ge 20 ] && echo yes || echo "no (scanned $_epipe_scanned)")" "yes"

test/selftest/320-a-check-that-could-not-run.sh

@@ -391,8 +391,16 @@ check "and a skip does not, which is the one that must stay true" \
 check "the runner's INCOMPLETE branch calls the mapping rather than a local flag" \
 	"$(grep -c 'pgc_verdict_fails_major "\$_verdict"' "$_rv")" "1"
 
+# CODE ONLY, NOT THE PROSE THAT DESCRIBES IT (#1123). `$_rv` carries 874 comment
+# lines, and one of them writing `MAJOR_FAIL=` -- a historical note about the very
+# name this arm exists to keep retired -- reddens it against a correct runner.
+# MEASURED, not supposed: adding that one comment line and changing nothing else
+# took harness_selftest to `1080 passed + 1 failed`.
+#
+# A herestring, not a pipe, because this file forbids the pipe (#486, part 080).
+_rv_code="$(grep -vE '^[[:space:]]*#' "$_rv")"
 check "and no write-only failure flag survives in the runner" \
-	"$(grep -c 'MAJOR_FAIL=' "$_rv")" "0"
+	"$(grep -c 'MAJOR_FAIL=' <<<"$_rv_code" || true)" "0"
 
 unset -f pgc_verdict_fails_major
 unset _rv _rvlog _rvrc