bumptech/glide · error · IllegalArgumentException

Unrecognized annotation: {}

Error message

Unrecognized annotation: {}

What it means

IndexerGenerator.getAnnotationValue maps an annotation class to its indexer key string ('modules' for GlideModule, 'extensions' for GlideExtension). Any other annotation class is unsupported and rejected defensively. This is a developer-only path inside the processor; users cannot trigger it through normal @GlideModule/@GlideExtension usage.

Source

Thrown at annotation/compiler/src/main/java/com/bumptech/glide/annotation/compiler/IndexerGenerator.java:128

    if (indexerName.length() >= (MAXIMUM_FILE_NAME_LENGTH - INDEXER_NAME_PREFIX.length())) {
      indexerName =
          INDEXER_NAME_PREFIX
              + UUID.nameUUIDFromBytes(indexerName.getBytes()).toString().replace("-", "_");
    }

    return TypeSpec.classBuilder(indexerName)
        .addAnnotation(annotationBuilder.build())
        .addModifiers(Modifier.PUBLIC)
        .build();
  }

  private static String getAnnotationValue(Class<? extends Annotation> annotation) {
    if (annotation == GlideModule.class) {
      return "modules";
    } else if (annotation == GlideExtension.class) {
      return "extensions";
    } else {
      throw new IllegalArgumentException("Unrecognized annotation: " + annotation);
    }
  }
}

View on GitHub (pinned to eb14a895d8)

Solutions

1. If you forked Glide's compiler, extend getAnnotationValue to handle your new annotation class.
2. Otherwise, report it as a Glide compiler bug with the full stack trace and Glide version.

When it happens

Trigger: IndexerGenerator.getAnnotationValue: `if (annotation == GlideModule.class) ... else if (annotation == GlideExtension.class) ... else throw`. Only reachable if internal Glide code calls getAnnotationValue with a different annotation type — i.e. an internal/programming error, not a user-annotation problem.

Common situations: Effectively unreachable for end users; would indicate a Glide compiler bug or a forked/modified processor that introduced a new indexer annotation without updating getAnnotationValue.

Related errors

• Unrecognized type: {}
• Given both modules and extensions, expected one or the other
• Cannot process annotations after writing AppGlideModule
• Expected single value, but found: {}
• Constructor for {} accepts too many parameters, it should ac

AI-assisted analysis of bumptech/glide@eb14a895d8 (2026-08-14). Data as JSON: /api/errors/0f7a89d7f3e0fc17. Report an issue: GitHub.