Humanizr/Humanizer · error · InvalidOperationException

{subject} references unknown source '{source}'.

Error message

{subject} references unknown source '{source}'.

What it means

Every source ID referenced in an evidence block's 'sources:' list must be declared in the inflection catalog's top-level source definitions. This validator walks the sources array and rejects any ID not present in the known sourceIds set, preventing evidence from pointing at nonexistent provenance records.

Source

Thrown at src/Humanizer.SourceGenerators/Generators/ProfileCatalogs/InflectionCatalogValidation.cs:103

            var correct = GetRequiredInt(values, "correct", $"Productive evidence '{direction}' must define correct");
            if (attempted < 100 || correct < 0 || correct > attempted ||
                correct * 100L < attempted * 99L)
            {
                throw new InvalidOperationException(
                    $"Productive evidence '{direction}' requires at least 100 attempts and 99% correctness.");
            }
        }

        static void ValidateSources(
            SimpleYamlMapping mapping,
            ImmutableHashSet<string> sourceIds,
            string subject)
        {
            foreach (var source in GetRequiredStrings(mapping, "sources", $"{subject} must define sources"))
            {
                if (!sourceIds.Contains(source))
                {
                    throw new InvalidOperationException($"{subject} references unknown source '{source}'.");
                }
            }
        }

        static void ValidateSourceDefinitions(SimpleYamlMapping sources)
        {
            foreach (var entry in sources.Values)
            {
                if (entry.Value is not SimpleYamlMapping source ||
                    source.GetScalar("kind") is not { Length: > 0 } ||
                    source.GetScalar("locator") is not { Length: > 0 })
                {
                    throw new InvalidOperationException(
                        $"Inflection source '{entry.Key}' must define non-empty kind and locator.");
                }

                ValidateProperties(
                    source,

View on GitHub (pinned to ffc2b77c0f)

Solutions

1. Add a matching source definition entry under the catalog's 'sources:' mapping with the referenced ID, including kind and locator.
2. Fix the typo in the evidence 'sources:' list to match an existing source ID exactly.
3. Remove the orphaned source reference from the evidence block if the source is no longer relevant.

Example fix

# before
sources:
  ud274:
    kind: 'treebank'
    locator: '...'
evidence:
  pluralize:
    sources: ['ud275']
# after
sources:
  ud274:
    kind: 'treebank'
    locator: '...'
evidence:
  pluralize:
    sources: ['ud274']

# Before building, verify every referenced source ID exists in the sources mapping.
python3 -c "
import yaml, sys
for f in sys.argv[1:]:
    d = yaml.safe_load(open(f))
    infl = d.get('inflection',{})
    declared = set((infl.get('sources') or {}).keys())
    ev = infl.get('evidence',{})
    for direction in ('pluralize','singularize'):
        for src in (ev.get(direction,{}).get('sources') or []):
            if src not in declared:
                print(f'{f}: evidence {direction} references unknown source {src!r}')
" src/Humanizer/Locales/*.yml

When it happens

Trigger: An evidence block (or any ValidateSources caller) lists a source string that does not match any key in the catalog's 'sources:' mapping. For example, evidence references 'ud2.15' but the sources section only defines 'ud2.14'.

Common situations: Renaming a source ID without updating all references. Copying an evidence block from another locale and forgetting to add the corresponding source definition. Typo in the source ID.

Related errors

• Inflection source '{entry.Key}' must define non-empty kind a
• Inflection source '{entry.Key}' {optionalProperty} must be a
• '{path}' must define provenance.
• '{path}.provenance' must be a sequence.
• '{path}.provenance' must contain non-empty source identifier

AI-assisted analysis of Humanizr/Humanizer@ffc2b77c0f (2026-08-13). Data as JSON: /api/errors/5a4a3d3bd23f1f31. Report an issue: GitHub.