Excluding Certain .C Files - Experimental Gradle Plugin

I’m using Gradle 2.6 with the gradle-experimental:0.3.0-alpha7 plugin. I would like to exclude some .C files from being included in my compilation. How do I do that without physically moving/deleting them?

I can’t seem to use the exclude/excludes keyword - I receive a complaint about it being deprecated and that I should “use the inputs property instead”. How do I do this?

I found the documentation on FileTree too - that looked like a really good way of sorting which files I want to include - but I guess this 2.8 API functionality isn’t available to me using Gradle 2.6?? I tried using Gradle 2.8 and then I was told I had to use 2.6 (presumably a plugin dependency?)

  android.sources {
        main.jni {
            source {
                srcDirs += ['src/main/jni/src']
                srcDirs += ['src/main/jni/SDL2/src']

                //FileTree tree = fileTree(dir: 'src/main')
                //excludes += 'src/main/jni/SDL2/src/audio/coreaudio/SDL_coreaudio.c'