def "can manually define C source sets"() {
        given:
        helloWorldApp.library.headerFiles.each { it.writeToDir(file("src/shared")) }

        file("src/main/c/main.c") << helloWorldApp.mainSource.content
        file("src/main/c2/hello.c") << helloWorldApp.librarySources[0].content
        file("src/main/sum-sources/sum.c") << helloWorldApp.librarySources[1].content

        and:
        buildFile << """