The second access-control screen spun for 2h20m on one ordinary mage-ai change: a Next.js build commit whose 3 MB
one-line bundles hold 12,355 functions each. `source.ranges_from_ir` ran two regex scans of the whole line once per
function, and the screen kept its 422 finished changes in memory only, so stopping it lost them.
- `source.ranges_from_ir`: a line over MINIFIED_LINE_CHARS (2000) is not checked per function; JavaScript names on it
stay anonymous, other languages keep the parser's name.
- `source.generated_reason`: why a changed file is build output (a directory the product walk leaves out, a minified
name, over MAX_FILE_BYTES, a line over the cap). `hunt.producers._candidates` leaves such files out and records the
reason on the context; the fix site of a vulnerability is always kept. The DSPy arm shares the enumeration.
- The screen writes rows.jsonl and log.jsonl per change (rows first, entry last) and resumes by skipping logged ids.
Tests: the minified line never reaches the per-function scan; generated_reason on the four shapes and two source files;
build output in an ordinary change yields no rows while a vulnerability path in a one-line file is kept.
Co-Authored-By: Claude Fable 5.1 <[email protected]>
Two instrument findings from the first access-control feature table (952 rows, 74 positive rows):
1. A fix that adds a guard is, replayed base-to-head, a push that removes it. The diff producer only kept
hunks with added lines at head, so 38 of 74 positive rows had no hunk in their file at all and 69 of 74
were "not on a changed line", while 60% of ordinary rows were. The diff annotation separated the labels
by construction and was blind to exactly the access-control shape. The producer (version 2) now records
per file the head lines after which the push removed code; distance and on_changed_line count them, the
model's hunks input renders them as removed_after_line, and diff.deletion_count is an engineered feature.
2. 150 rows (16%, every positive of one repository) read empty files from the worktree although git holds
the blobs; the build ran while another process checked out from the same clone. _full_checkout now
proves the checkout: git status must be clean, a dirty tree is restored once, then InstrumentFailure
checkout_incomplete. The table script cross-checks every unread row against the blob size and refuses
to screen a partly unread tree, and records the diff-scoped recall ceiling (positive rows a label-blind
enumeration would reach).
Co-Authored-By: Claude Fable 5.1 <[email protected]>
