jstests/noPassthrough/extensions/extension_docs_needed_bounds.js was failing on all-non-rollback-feature-flags variants with: The $testFoo stage should be loaded by the libfoo_mongo_extension extension. If this extension is loaded, we expect this error to be silently skipped. (Location10918500) The test uses $testFoo, which has a stub parser registered in aggregation_stage_fallback_parsers.json gated on the IFR flag featureFlagExtensionStubParsers. On all-non-rollback-feature-flags builds, this IFR flag is force-enabled at runtime. When both the stub (fallback) and the real extension parser (primary) are registered, LiteParserRegistration::getParserInfo() selects between them based on the flag, with the flag enabled, the stub fires instead of the real parser. Fix: add featureFlagExtensionStubParsers to the test's @tags so it only runs in the correct flag state. This is the same fix applied in SERVER-127738 (extension_on_view_after_vector_search.js) and SERVER-120419 for other $testFoo tests.