Arclight/build.gradle

import java.nio.file.*
import java.nio.file.attribute.BasicFileAttributes

allprojects {
    group 'io.izzel.arclight'
    version '1.0.3'

    ext {
        agpVersion = '1.7'
    }

    task cleanBuild {
        doFirst {
            def f = project.file("build/libs")
            if (Files.exists(f.toPath())) {
                Files.walkFileTree(f.toPath(), new SimpleFileVisitor<Path>() {
                    @Override
                    FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
                        Files.delete(file)
                        return FileVisitResult.CONTINUE
                    }

                    @Override
                    FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
                        Files.delete(dir)
                        return FileVisitResult.CONTINUE
                    }
                })
            }
        }
    }
}

task collect(type: Copy) {
    destinationDir = file('build/libs')
    subprojects.each { p ->
        from p.file('build/libs')
    }
}