stanfordnlp/CoreNLP · error · RuntimeException

Cannot find gold mention with ID=

Error message

Cannot find gold mention with ID=

What it means

Document.extractGoldLinks throws when a gold Mention's originalRef points to a mention ID absent from the document's positions map — i.e., the gold coreference chain references a mention that was never extracted. This is a data consistency failure in gold annotations.

Solutions

  1. Regenerate or re-download the gold corpus files and verify integrity
  2. Check that mention extraction settings match the gold data format (no filtering that drops referenced mentions)
  3. Pre-validate gold data: every non-negative originalRef must map to an existing mention
  4. Run on the official supported CoNLL-2012 gold files rather than converted/modified copies
Defensive patterns

Strategy: validation

Validate before calling

for (List<Mention> ms : doc.goldMentions)
  for (Mention m : ms)
    if (m.originalRef >= 0 && !doc.positions.containsKey(m.originalRef))
      throw new IllegalStateException("Dangling gold ref: " + m.originalRef);

Try / catch

try {
  doc.getGoldLinks();
} catch (RuntimeException e) {
  if (e.getMessage() != null && e.getMessage().startsWith("Cannot find gold mention with ID=")) {
    logger.severe("Gold data corrupt; regenerate gold files: " + e.getMessage());
  } else throw e;
}

Prevention

When it happens

Trigger: extractGoldLinks (via getGoldLinks) processing gold CoNLL annotations where m.originalRef >= 0 but positions.get(m.originalRef) returns null — a dangling reference in the gold data or mention filtering removed the referenced mention.

Common situations: Corrupted or hand-edited gold CoNLL files; preprocessed corpora where mentions were filtered but reference links were not updated; version mismatch between mention extraction and gold data format.

Understand the failure class

Background: "Not found" and "does not exist" errors: why "Task not found", "No such folder", and "Can't find" fire when a lookup comes back empty — this error's family across 14 libraries.

Related errors

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/12a5153ffd9379af. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/coref/data/Document.java:290

        IntTuple pos = new IntTuple(2);
        pos.set(0, i);
        pos.set(1, j);
        positions.put(id, pos);
        antecedents.put(id, new ArrayList<>());
      }
    }

//    SieveCoreferenceSystem.debugPrintMentions(System.err, "", goldOrderedMentionsBySentence);
    for (List<Mention> mentions : goldMentions) {
      for (Mention m : mentions) {
        int id = m.mentionID;
        IntTuple src = positions.get(id);

        assert (src != null);
        if (m.originalRef >= 0) {
          IntTuple dst = positions.get(m.originalRef);
          if (dst == null) {
            throw new RuntimeException("Cannot find gold mention with ID=" + m.originalRef);
          }

          // to deal with cataphoric annotation
          while (dst.get(0) > src.get(0) || (dst.get(0) == src.get(0) && dst.get(1) > src.get(1))) {
            Mention dstMention = goldMentions.get(dst.get(0)).get(dst.get(1));
            m.originalRef = dstMention.originalRef;
            dstMention.originalRef = id;

            if (m.originalRef < 0) break;
            dst = positions.get(m.originalRef);
          }
          if (m.originalRef < 0) continue;

          // A B C: if A<-B, A<-C => make a link B<-C
          for (int k = dst.get(0); k <= src.get(0); k++) {
            for (int l = 0; l < goldMentions.get(k).size(); l++) {
              if (k == dst.get(0) && l < dst.get(1)) continue;
              if (k == src.get(0) && l > src.get(1)) break;

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