Incremental Builds are a great optimization that helps avoid work already done.
If a developer continuously changes a single file, there is likely no need to rebuild all the other files in the project.

However, what happens when the same developer switches to a new branch created last week?
The files are rebuilt, even though the developer is building something that has been built before.

This is where a *build cache* is helpful.

Class <org.gradle.nativeplatform.internal.prebuilt.DefaultPrebuiltLibraries> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (DefaultPrebuiltLibraries.java:0)
Class <org.gradle.nativeplatform.internal.prebuilt.DefaultPrebuiltLibrary> is not annotated (directly or via its package) with @org.gradle.api.NonNullApi in (DefaultPrebuiltLibrary.java:0)

However, what happens when the same developer decides to switch to a new branch created last week?
The files are rebuilt, even though the developer is building something that has been built before.

This is where a Build Cache is helpful. The cache stores previous build results, and greatly reduces the need to rebuild things when they have already been built locally.

        }
        FileLock fileLock = lockManager.lock(lockTarget, lockOptions, cacheDisplayName);
        try {
            boolean rebuild = initializationAction.requiresInitialization(fileLock);
            if (rebuild) {
                Exception latestException = null;
                for (int tries = 0; rebuild && tries < 3; tries++) {
                    fileLock.close();
                    fileLock = null;

	// DeletedClusters contains list of all subset clusters for the deleted DR or updated DR.
	// When clusters are rebuilt, we rebuild the subset clusters as well. So, we know what
	// subset clusters are really needed. So if deleted cluster is not rebuilt, then it is really deleted.
	builtClusters := sets.New[string]()
	for _, c := range clusters {
		builtClusters.Insert(c.Name)
	}

        }
        final FileLock fileLock = lockManager.lock(lockTarget, lockOptions, cacheDisplayName, "", unused -> {});
        try {
            boolean rebuild = initializationAction.requiresInitialization(fileLock);
            if (rebuild) {
                fileLock.writeFile(() -> initializationAction.initialize(fileLock));
            }
            onOpenAction.accept(fileLock);
        } catch (Exception e) {

            def changes = delegateContext.changes.get()
            assert delegateContext.rebuildReasons == ImmutableList.of("Forced rebuild.")
            assert !changes.createInputChanges().incremental
            return delegateResult
        }
        _ * context.nonIncrementalReason >> Optional.of("Forced rebuild.")
        _ * context.beforeExecutionState >> Optional.of(beforeExecutionState)
        0 * _
    }

[short] skip 'compiles and links executables'

# Set up fresh GOCACHE.
env GOCACHE=$WORK/gocache
mkdir $GOCACHE

# build without PGO
go build triv.go

# build with PGO, should trigger rebuild
# starting with an empty profile (the compiler accepts it)
go build -x -pgo=prof -o triv.exe triv.go
stderr 'preprofile.*-i.*prof'
stderr 'compile.*-pgoprofile=.*triv.go'

# check that PGO appears in build info

            include("a")
            include("b")
            rootProject.name = "root"
        """
        apply(testDirectory)
        apply(file("a"))
        apply(file("b"))

        // Prebuild buildSrc
        server.expect("configure-root")
        server.expect("configure-a")
        server.expect("configure-b")
        run()

        given:
        server.expect("configure-root")

        }

        then:
        0 * _  // Does not call initialization action.
        dir.file("cache.properties").isFile()
        dir.file("some-file").isFile()
    }

    def "will rebuild cache if not unlocked cleanly"() {
        given:
        def dir = temporaryFolder.testDirectory.createDir("cache")
        def initialized = false
        def init = { initialized = true } as Consumer