Resolved 4 conflicts: cli.py (R-D citing-coverage warning + main's small-corpus JSON/hub-title changes both kept); ingest.py (C-7 paper.id=caller-id pin first, then DQ-2 abstract recovery); test_ingest.py + test_openalex.py (kept both branches' tests).
C-7/DQ-5 overlap (both canonicalise papers.id): kept both layers — openalex._canonical_id normalizes fetch_paper's id (DQ-5); ingest pins papers.id to the caller's bare id (C-7); they converge on the bare canonical id. Fixed the auto-merged test_fetch_paper_success that had contradictory bare/URL assertions. 402 tests pass; ruff + mypy clean.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Three papers lacked abstracts and 1911.00966 was fully degraded (OpenAlex 404
-> empty `Paper(id, title="")` stub). Recovery sources verified, then wired in:
- arxiv.fetch_metadata: resolve an arXiv id to a Paper via the Atom export API
(authoritative for preprints). Used as an ingest fallback on OpenAlex 404,
replacing the empty stub.
- crossref.py (new): fetch_abstract(doi), JATS-stripped, Crossref Polite Pool.
- semanticscholar.fetch_abstract: fetch just the abstract field.
- ingest.py: _recover_abstract() supplements an empty abstract from S2 then
Crossref *before* embedding, so the paper gets a real (non-zero) vector.
Live DB backfill: 1911.00966 fully recovered from arXiv (bibkey
PinkallSpringborn2019, 384-char abstract, its 10 chunks now visible to chunk
search); 10.1007/s00454-019-00132-8 abstract from S2 (1186 chars). Book chapter
10.1007/978-3-642-17413-1_7 has no abstract in OpenAlex/S2/Crossref -> documented
limit. Corpus now has 1 paper without an abstract.
Also documented DQ-5 (not fixed): ingest_paper is not idempotent for DOI papers
(openalex returns full-URL id vs the bare canonical id) -> re-ingest trips
papers_openalex_id_key. Blocks roadmap R-A/R-C; needs a careful _map_paper fix.
Tests: arxiv/crossref/s2 fetchers + ingest recovery paths (342 passing).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
12/29 papers had zero citations: OpenAlex indexes arXiv preprints and theses
without a parsed reference list (verified referenced_works_count=0 server-side
for all 11 with an openalex_id). Not an ingest bug — a source-coverage limit.
- ingest.py: when OpenAlex returns no references, fall back to a Semantic
Scholar reference supplement (_s2_reference_supplement); citing_id rewritten
to canonical papers.id, DOI cited-ids lowercased. Removed a now-redundant
discarded S2 probe in the OpenAlex-404 arXiv branch.
- semanticscholar.py: fix TypeError on S2's HTTP-200 {"data": null} no-refs
responses (.get("data", []) returns None when the key is present-but-null).
- tests: regression test for the OpenAlex-empty -> S2 path.
- Live DB backfilled idempotently: +330 citations (590->920), zero-out-edge
papers 12->2, citing coverage 17->27/29. Only the 2 TU-Berlin depositonce
theses remain (no references in any source).
- docs: DATA-QUALITY-2026-06-15.md — DQ-1 resolution, DQ-4 result, and a
free-source acquisition roadmap (R-A..R-E).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
- R-4: arxiv.fetch_source had a try/except httpx.RequestError that only re-raised
— removed (no behaviour change, less noise).
- R-5: semanticscholar URLs now quote(paper_id, safe=':') so a legacy-arXiv '/'
(arXiv:math/0603097) doesn't corrupt the path and silently return no references.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Committed code predated the line-length=100 ruff config; this brings the
five drifted files into compliance. No logic change.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
