bumptech/glide · error · IllegalArgumentException

Given both modules and extensions, expected one or the other

Error message

Given both modules and extensions, expected one or the other. Modules: {} Extensions: {}

What it means

Each generated Indexer class bundles either modules OR extensions, never both, because they are indexed separately downstream. IndexerGenerator.generate throws when, after classification, both the `modules` and `extensions` lists are non-empty for the same indexer batch — an internal invariant violation indicating mixed classification input.

Source

Thrown at annotation/compiler/src/main/java/com/bumptech/glide/annotation/compiler/IndexerGenerator.java:71

  IndexerGenerator(ProcessorUtil processorUtil) {
    this.processorUtil = processorUtil;
  }

  TypeSpec generate(List<TypeElement> types) {
    List<TypeElement> modules = new ArrayList<>();
    List<TypeElement> extensions = new ArrayList<>();
    for (TypeElement element : types) {
      if (processorUtil.isExtension(element)) {
        extensions.add(element);
      } else if (processorUtil.isLibraryGlideModule(element)) {
        modules.add(element);
      } else {
        throw new IllegalArgumentException("Unrecognized type: " + element);
      }
    }
    if (!modules.isEmpty() && !extensions.isEmpty()) {
      throw new IllegalArgumentException(
          "Given both modules and extensions, expected one or the "
              + "other. Modules: "
              + modules
              + " Extensions: "
              + extensions);
    }
    if (!modules.isEmpty()) {
      return generate(types, GlideModule.class);
    } else {
      return generate(types, GlideExtension.class);
    }
  }

  private TypeSpec generate(
      List<TypeElement> libraryModules, Class<? extends Annotation> annotation) {
    // Sort modules by qualified name to ensure deterministic ordering
    List<TypeElement> sortedModules = new ArrayList<>(libraryModules);
    sortedModules.sort(Comparator.comparing(a -> a.getQualifiedName().toString()));

View on GitHub (pinned to eb14a895d8)

Solutions

1. Inspect the printed modules/extensions lists and ensure no class is both a LibraryGlideModule and a @GlideExtension — split them.
2. Clean and rebuild to rule out stale indexer inputs.
3. Align Glide dependency versions across modules.

When it happens

Trigger: IndexerGenerator.generate: `if (!modules.isEmpty() && !extensions.isEmpty()) throw`. Reached only if the same batch contains elements classified as both a LibraryGlideModule and a GlideExtension — which should not happen for well-formed classes (a class cannot validly be both).

Common situations: A class that somehow has both @GlideExtension and extends LibraryGlideModule (or is detected as both); a custom/buggy annotation setup; incremental cache feeding a mixed batch; an upstream Glide bug.

Related errors

• Unrecognized type: {}
• Unrecognized annotation: {}
• 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/9a65ac81c8e5a0ba. Report an issue: GitHub.