Gradle: how to copy subproject jar to another subp

问题:

I have the following multiproject structure in Gradle:

- root-project
  - acceptance-tests
  - sub-java-proj

acceptance-tests has a task cucumber (provided by Gradle Cucumber-plugin) which runs the Cucumber features in the project. However, I need to do some bootstrapping before the features are run. In particular, before thecucumber task Gradle should do the following:

1. Run tests in sub-java-proj and if they pass produce its jar file (if not fail)
2. Copy the jar file from 1) into the directory accentance-tests/proglib
3. Run the Cucumber features like normal
4. Delete the jar file copied in 2)

I'm completely new to Gradle so I am not sure how to properly implement this. My first thought was to make acceptance-tests depend on sub-java-proj (with testRuntime config), but I feel this is an abuse of the dependency mechanism: the only reason to do this is to ensure sub-java-proj is compiled before acceptance-tests is run, but in reality this also messes with the classpath of acceptance-tests by adding the jar from sub-java-proj and there's also problems with transitive dependencies. In short: acceptance-tests should not have anything to do with sub-java-proj besides copying it's jar around.

Suggestions on how to accomplish this are very much appreciated.

Update

So far I have the followingin acceptance-tests/build.gradle:

task fix(dependsOn: ':sub-java-proj:jar', type: Copy) {
    from tasks.getByPath(':sub-java-proj:jar')
    to 'proglib'
}

task unfix(type: Delete) {
    delete fix
}

cucumber.dependsOn fix
cucumber.finalizedBy unfix

However, this works except that unfix deletes the proglib directory too. It should only delete the jar file. Any ideas how to fix this?