Grails 3.0.5 - 3.0.8 Using a Pathing Jar causes a Circular Dependency Error

[lhigginbotham]

Environment:

Windows 7 64-Bit
| Grails Version: 3.0.8
| Groovy Version: 2.4.4
| JVM Version: 1.8.0_45

Reproducible Example:
https://github.com/lhigginbotham/grailspathingjarissue
When attempting to build a project using a pathing jar in Grails 3.0.5 and above, I get the following error. The code works in Grails 3.0.4.

FAILURE: Build failed with an exception.

* What went wrong:
Circular dependency between the following tasks:
:classes
\--- :compileGroovy
     \--- :launcherJar
          \--- :compileGroovyPages
               +--- :compileGroovy (*)
               +--- :compileIntegrationTestGroovy
               |    +--- :classes (*)
               |    +--- :compileIntegrationTestJava
               |    |    +--- :classes (*)
               |    |    \--- :testClasses
               |    |         +--- :compileTestGroovy
               |    |         |    +--- :classes (*)
               |    |         |    \--- :compileTestJava
               |    |         |         \--- :classes (*)
               |    |         \--- :compileTestJava (*)
               |    \--- :testClasses (*)
               \--- :compileTestGroovy (*)

(*) - details omitted (listed previously)

I'm using some code that collects all the runtime dependencies into a single jar to bypass Window's native command line string length limitations.

task launcherJar(type: Jar) {
    def gradleUserHome = new File(gradle.getGradleUserHomeDir(), "caches")

    def relativeClasspathEntries = configurations.runtime.files.collect {
        new File(gradleUserHome.getAbsolutePath()).toURI().
                relativize(new File(it.getAbsolutePath()).toURI()).getPath()
    }
    appendix = "launcher"
    destinationDir = gradleUserHome
    doFirst {
        manifest {
            attributes "Class-Path": relativeClasspathEntries.join(" ")
        }
    }
}

compileGroovy{
  dependsOn launcherJar
    FileCollection collection = files(launcherJar.archivePath);
    def finCollection = collection
    doLast {
        classpath = finCollection
    }
}

bootRun{
    doFirst{
        //The main build directories aren't collected so they are added manually
        FileCollection collection = files("${project.buildDir}/classes/main") + files("${project.buildDir}/resources/main") + files(launcherJar.archivePath)
        classpath = collection
    }
}

I'm not sure, but I think the changes for #9165 might be what has caused the issue.

[gregopet]

Can someone from the Grails' side provide any clues on how merge pathing JARs with Asset Pipeline (see the referenced issue)?