public void execute(InputChanges inputChanges) {
        Set<File> grammarFiles = new HashSet<>();
        FileCollection stableSources = getStableSources();
        if (inputChanges.isIncremental()) {
            boolean rebuildRequired = false;
            for (FileChange fileChange : inputChanges.getFileChanges(stableSources)) {
                if (fileChange.getFileType() == FileType.FILE) {

        FileCollection stableSources = getStableSources();
        return new GroovyRecompilationSpecProvider(
            getDeleter(),
            getServices().get(FileOperations.class),
            stableSources.getAsFileTree(),
            inputChanges.isIncremental(),
            () -> inputChanges.getFileChanges(stableSources).iterator()
        );
    }

    /**

        performCompilation(spec, compiler);
    }

    private Compiler<JavaCompileSpec> makeIncremental(InputChanges inputs, CleaningJavaCompiler<JavaCompileSpec> compiler, FileCollection stableSources) {
        FileTree sources = stableSources.getAsFileTree();
        return getIncrementalCompilerFactory().makeIncremental(
            compiler,
            sources,
            createRecompilationSpec(inputs, sources)
        );

            normalization == "CLASSPATH"
            attributes == ['DIRECTORY_SENSITIVITY_DEFAULT', 'FINGERPRINTING_STRATEGY_CLASSPATH', 'LINE_ENDING_SENSITIVITY_DEFAULT']
        }

        with(aCompileJava.stableSources) {
            hash != null
            normalization == "RELATIVE_PATH"

.
.
.
Appending input file fingerprints for 'options.sourcepath' to build cache key: 5fd1e7396e8de4cb5c23dc6aadd7787a - RELATIVE_PATH{EMPTY}
Appending input file fingerprints for 'stableSources' to build cache key: f305ada95aeae858c233f46fc1ec4d01 - RELATIVE_PATH{.../src/main/java=IGNORED / DIR, .../src/main/java/Hello.java='Hello.java' / 9c306ba203d618dfbe1be83354ec211d}

        outputContains("Appending input value fingerprint for 'options.fork'")
        outputContains("Appending input file fingerprints for 'classpath'")
        def sourcesDebugLogging = "Appending input file fingerprints for 'stableSources' to build cache key: "
        outputContains(sourcesDebugLogging)
        outputContains("Build cache key for task ':compileJava' is ")