hearth-cross-compilation

Scala macro cross-compilation fails due to subtle differences in path-dependent types, splice isolation, and type constructor matching. Identifying these version-specific pitfalls ensures robust macro expansion and prevents divergent runtime behavior across Scala 2.13 and Scala 3.

Handling path-dependent types and splice isolation requires careful quote scoping to avoid reification failures. Applying safe extension patterns and understanding Scala 3 quote semantics maintains consistent macro behavior when porting Scala 2.13 macro logic.

Common macro pitfalls include Array ClassTag mismatches, upcast semantics differences, phantom types, and IsMap or IsCollection ordering. Reviewing a comprehensive pitfalls reference helps avoid brittle code and resolve these edge cases before runtime.

Cross-compilation impacts LambdaBuilder scope and def-caching strategies, requiring specific guidance to maintain consistent macro expansion. Properly managing these loading and caching mechanisms ensures extension code compiles identically across both Scala versions.

Check for IsCollection and IsMap ordering issues when macro derivation behaves differently across Scala versions. Addressing these type constructor matching and reification failures early ensures your dual-version extension code remains stable and avoids runtime errors.