known-issues

CPython Known-Issues Regression

data/cpython_known_bugs.tsv records crash sites previously confirmed in CPython — from the findings repos (OOM-####, TSAN-####) and the upstream tracker (gh-NNNNNN). This command runs, per catalog entry, the scanner matching that entry's category over the referenced file and reports whether the known bug is still in the tree.

It is static and drift-tolerant — it does not run repros. It answers: "of the crashes we already know about, which are still present at this checkout, which have drifted, and which look fixed?"

Scope: "$ARGUMENTS" (path or glob; default the whole project). The scope's checkout root is auto-detected — catalog paths are resolved relative to it, so a narrow scope still locates the right files.

Plugin root: <plugin_root> is the plugins/cpython-review-toolkit/ directory.

Category → scanner map

Category	Scanner
recursion	scan_recursion_guards.py
pyerr-clear	scan_pyerr_clear.py
uninit-dealloc	scan_uninit_dealloc.py
null-deref	scan_null_checks.py
refcount	scan_refcounts.py
tsan	scan_ft_races.py
init-bypass	scan_init_bypass.py

Every shipped category has a scanner as of v0.7 — no_scanner: 0 is the expected result, and a non-zero count means a category was added to the catalog before its scanner. Preserve that invariant when extending the catalog.

Workflow

1. Cross-reference:

   python <plugin_root>/scripts/check_known_issues.py [scope]
   

   Optional flags: --max-files N, --catalog <path> (override the default TSV). Record the reviewed commit (git -C <project_root> rev-parse --short HEAD) — the catalog was captured at a slightly different commit, so line drift is expected.

2. Read the catalog_results / bug_rollup blocks. Each entry gets one of:

   • present — a finding of that category at (or within ±5 lines of) the catalog line, or — when the catalog line is unknown (0) — a finding in the named function. Still unfixed. → high confidence.
   • line_drifted — the file still has findings of that category but not at the catalog site, and the catalog's named function is gone (renamed/removed) or was never recorded (0). nearest_line points at the closest finding. The bug likely just moved. → medium.
   • absent_in_function — the catalog names a function, that function still exists in the file, and it carries no finding of the category — while the file has findings elsewhere. This is absence in that function, not drift. Drift says "still there, moved"; this says "possibly fixed here". → weak signal, not a finding.
   • absent — the file was scanned and has no findings of that category anywhere (likely fixed or refactored).
   • file_missing — the path no longer exists under the checkout.
   • no_scanner — a catalog category with no entry in CATEGORY_SCANNERS; carried through for completeness, not cross-referenced. As of v0.7 every shipped category has a scanner, so this should read 0.