Dependency resolution should be optional

[karypid]

Hello,

I am writing to raise awareness to an issue in exec-maven-plugin that prevents it from being used in the generate-sources phase. The problem is that it uses "requiresDependencyResolution = ResolutionScope.TEST" (see: https://github.com/mojohaus/exec-maven-plugin/blob/master/src/main/java/org/codehaus/mojo/exec/ExecJavaMojo.java) which means that it cannot be invoked before the compile phase (even though a typical use of this plugin is in generate-sources to invoke code generators).

Basically, I think that the annotation should be removed and replaced with programmatically checking whether dependencies are available when "includeProjectDependencies" in the configuration is true.

Resources:

[1] Issue raised in Maven side: https://issues.apache.org/jira/browse/MNG-3283

[2] My SO question: https://stackoverflow.com/questions/50288587/how-does-maven-decide-when-to-use-the-target-folder-for-classpath

[3] Discussion in Maven user list: http://maven.40175.n5.nabble.com/Problem-with-exec-maven-plugin-td5934208.html