Plexus and Maven

Prior to Maven 3.9, a component named plexus-tools was included by Apache Maven at runtime. The component is used by Maven plugin internals. In v3.9.0 of Maven, this was removed. Some older Maven plugins may still need this dependency to work. The protobuf-maven-plugin does not require this, but we have observed in some cases that Maven still attempts to reference this dependency (likely triggered by the use of Maven 2 plugins that need to be updated by the author). This can result in the protobuf-maven-plugin crashing with “wiring” errors. See this discussion for details and a potential workaround while this is investigated.

Incremental compilation edge cases

The experimental incremental compilation feature is known to have some edge cases where a mvn clean is required to rebuild the entire source tree. This is due to the somewhat coarse way that changes are monitored between builds. If this becomes overly problematic, please raise an issue on GitHub with details of how to reproduce the issue you are seeing.

Incremental compilation only currently considers if an entire file has changed. No attempt is made to parse a dependency graph of all sources to determine whether a change impacts other files. This may be implemented in the future if the performance overhead is not too high. For now, it is best to disable incremental compilation, use includes/excludes, or perform clean builds if you are actively changing protobuf sources.

Descriptor support

Protobuf descriptors are currently unsupported. Please raise an issue on GitHub if you wish to request this feature, along with details of your use case.