[MCHECKSTYLE-368] Missing test-jar on mvn compile

**[Adam Hornáček](https://issues.apache.org/jira/secure/ViewProfile.jspa?name=ahornace)** opened **[MCHECKSTYLE-368](https://issues.apache.org/jira/browse/MCHECKSTYLE-368?redirect=false)** and commented

Hello,

we have a multi-module Maven project. One of the subprojects depends on test-jar. Everything seems to work fine until I enable Maven Checkstyle Plugin in this subproject. Then `mvn compile` target fails; however, `mvn package` works fine.

The error message:

```
[ERROR] Failed to execute goal on project opengrok-web: Could not resolve dependencies for project org.opengrok:opengrok-web:war:1.2.1: Failure to find org.opengrok:opengrok:jar:tests:1.2.1 in http://repo.maven.apache.org/maven2/ was cached in the local repository, resolution will not be reattempted until the update interval of maven.org has elapsed or updates are forced -> [Help 1]
```

PR containing changes that cause this issue:
https://github.com/oracle/opengrok/pull/2259

Thanks.

---

**Affects:** 3.0.0

**Attachments:**
- [mvn_debug.out](https://issues.apache.org/jira/secure/attachment/12958999/mvn_debug.out) (_696.84 kB_)

Start by reviewing the attached mvn_debug.out and the changes in oracle/opengrok pull request 2259. Reproduce the difference between mvn compile and mvn package for the multi-module project with a test-jar dependency. Done means mvn compile resolves the test-jar when Maven Checkstyle Plugin is enabled.

Written by the indexing model from the issue text.