[MDEP-907] annotationProcessorPaths from maven-compiler-plugin are not resolved when using dependency:go-offline

**[Filip Hrisafov](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=filiphr)** opened **[MDEP-907](https://issues.apache.org/jira/browse/MDEP-907?redirect=false)** and commented

I am creating this bug in the Maven Compiler Plugin. However, I am not sure whether this is the right place. I appologize in advance if this is the wrong project.

I have noticed that using `mvn dependency:go-offline` will not resolve the dependencies defined in the `annotationProcessorPaths` of the maven-compiler-plugin.

I have created https://github.com/filiphr/maven-dependency-offline-annotation-processor-paths that demonstrates the problem.

I've had a look at MCOMPILER-391, but I don't think that this is related to this one. However, I also found MNG-6877 which might solve the problem if there is a dedicated scope for annotation processing and then the maven-dependency-plugin will correctly be able to resolve the annotation processors.

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No further details from [MDEP-907](https://issues.apache.org/jira/browse/MDEP-907?redirect=false)

Start with the linked maven-dependency-offline-annotation-processor-paths reproduction and run mvn dependency:go-offline to confirm the missing annotationProcessorPaths dependencies. Read the references to MCOMPILER-391 and MNG-6877, then determine what change would make those processors resolve during offline dependency resolution.

Written by the indexing model from the issue text.