-`deep` requests the REGRESS stage, which was retired on 2026-10-13: the scan records a `regress_retired` degradation and otherwise equals `standard`. Execution proof now comes from the search-with-proof arm.
| `standard` | MAP: complexity map, semantic overlay, authorization obligations, the Joern model layer; `fusion` (deterministic) | Joern; a provider key for the residual LLM question | `cpg_unavailable` degradation; the LLM's questions are skipped and only the graph's entailed findings are reported |
| `deep` | nothing today: REGRESS was retired on 2026-10-13 and is recorded as `regress_retired`; execution proof belongs to the search-with-proof arm | - | - |
**A new branch.** Git gives the hook no remote base for a branch the remote does not have yet.
The check says so ("new branch: the remote has no base to compare against"), runs the quick rules
over the files the branch's last commit changed instead, and says that too. Set
`OUSAST_COMPARISON_BASE=main` to compare a new branch against your local `main`.
**The engine and the deadline.** The engine does not fit a 30 s deadline today. The 2026-10-02
audit measured 260 s on a 26-file repository; graph reuse is the planned fix. When it cannot
finish, one line says so. With `OUSAST_PUSH_ENGINE=background`, the hook returns after the quick
rules and starts one detached engine run (`--background-deadline`, 900 s by default). The next push
in the same repository prints `Engine result for <head> from the previous push: ...` once. Only
one background run happens at a time. The Docker wrapper cannot run the engine in the background,
because the container ends with the hook.
**The artifact.** Every run writes one JSON file, and the terminal prints its path after
`Details:`. It records the following:
- `snapshots[].bytes_read`: proof that the input was read;
- `quick_tier`: the quick-rule matches, with the files and bytes read;
- `admission.coverage_reasons`: the raw skip reasons;
- `admission.dispositions`: every engine candidate and its vetoes;
- `engine_background`: background runs started or shown;
- `timings`.
Files accumulate, one per push; delete old ones when you like.
### Skip reasons
The terminal prints one `Skipped:` line per distinct reason in plain words. The artifact keeps the
raw reason. Repository paths are hex-encoded there, and per-question reasons end in a hash.
| Raw reason (artifact) | Terminal line says | What to do |
| --- | --- | --- |
| `cpg_build_failed`, `cpg_unavailable` | the engine did not run: the code graph could not be built | install Joern, or use the Docker wrapper |
| `cpg_empty` | the engine read no code | check that the changed files are in a supported language |
| `frontend_unsupported` | no engine frontend for a language in this push | none: that language gets the quick rules at most |
| `language_not_covered:<lang>:<changed>:<total>` | language not covered: `<lang>` (n changed files, m in the repository) | none: neither the engine nor the quick rules cover it, so silence is not a clean result |
| `deadline_exhausted` | the engine did not finish within the deadline | raise `OUSAST_PUSH_DEADLINE`, or set `OUSAST_PUSH_ENGINE=background` |
| `change_context_deadline_exhausted` | the deadline ran out while relating the change to the code | as above |
| `report_deadline_exhausted` | the deadline ran out while saving the details | as above |
| `engine_off`, `engine_background` | the engine was switched off, or runs after the push | none |
| `resolution:missing_base` | new branch: the remote has no base to compare against | set `OUSAST_COMPARISON_BASE` |
| `resolution:unsupported_base`, `resolution:no_merge_base`, `resolution:ambiguous_base`, `resolution:missing_target`, `resolution:unsupported_target`, `resolution:resolution_error` | the pushed ref or its remote base could not be resolved locally | fetch the remote, then push again |
| `base_comparison_unavailable`, `base_unavailable` | no base revision was analysed, so nothing can be called new | see the line before it for the cause |
| `base_counterpart_unresolved` | the changed code has no counterpart in the base to compare against | none: expected for new files |
| `<path>:ambiguous_line_correspondence`, `<path>:line_correspondence_unavailable`, `<path>:ambiguous_path_rename_correspondence` | changed lines or a renamed file could not be matched to the base | none: findings there stay diagnostic |
| `unmatched_added_deleted_path_correspondence` | files were both added and deleted, so a move cannot be told from a new file | push the move separately from other edits |
| `declaration_paths_unavailable` | project declaration files could not be listed | rerun |
| `capability_unavailable`, `capability_disabled`, `capability_unevaluated`, `capability_ambiguous` | engine findings are not qualified as alerts yet | none: they show as advisory engine findings |
| `eligibility:<reason>` | the capability registry does not match this build | reinstall a consistent build |
| `comparison_unknown`, `base_incomplete` and the other novelty reasons | whether this push introduced some engine findings could not be established | none: they stay diagnostic |
| `dynamic_external_or_depth_context_unresolved:...` | n engine checks depend on dynamic or external code the engine cannot follow | none |
| `query_failed`, `query_budget_reserved`, `query_too_expensive`, `regions_truncated`, `files_unparsed` | some engine questions were not answered | raise the deadline or `--max-regions` |
| `cross_partition_semantics_unresolved` | flows between languages are not followed | none |
| `dependency_unresolved`, `change_unsupported` | engine findings depend on unresolved code or have no supported link to the change | none |
| `snapshot:<reason>` | some files could not be materialised for analysis | see the reason (symlinks, submodules, LFS) |
| `<stage>_failed:<Error>`, `push_input_failed:<Error>` | the named step failed | rerun; report it if it repeats |
A reason not in this table is still printed as its own words, followed by "see the details file".
### In CI
The same check runs on a pushed range in CI. This GitHub Actions job is advisory: it never fails
