[MNG-7289] Tests of Forked Execution fails with Guice provision errors, while unforked succeeds

**[Robert Scholte](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=rfscholte)** opened **[MNG-7289](https://issues.apache.org/jira/browse/MNG-7289?redirect=false)** and commented

When checking out https://github.com/apache/maven-release/commit/6acc4ea3c0b0a011229497c60b99cfebf680d862 and run `mvn test` you'll see no issues.
However, if you run `mvn site -Preporting` you'll notice that the maven-surefire-report-plugin starts a fork calling the test phase. Here all tests fail with ComponentLookup error.
Maven succeeds, probably because it simply generates a report summarying the test results.
Jenkins on the other hand does detect these failures and makes the build fail.

For some reason in this case the component descriptors cannot be found. The workaround is to run `mvn package site -Preporting`

Interesting fact: current Maven 4 already fails on module 3 during compilation with `cannot find symbol`, I suspect MNG-6566 exposes the root cause earlier.

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**Affects:** 3.0-alpha-1, 3.6.3, 3.8.3