Flip --incompatible_no_implicit_watch_label

Fixes #23861

RELNOTES[inc]: `repository_ctx.path()` and `module_ctx.path()` no longer watch arguments of type `Label`. Use the `watch()` method or the `watch` parameter on other methods on these context objects instead. See #23861 for details.

Closes #23872.

PiperOrigin-RevId: 682413794
Change-Id: I22c9dd06b5c0f6c78302a28b52ca1f3e9a23507a

src/main/java/com/google/devtools/build/lib/packages/semantics/BuildLanguageOptions.java

@@ -287,7 +287,7 @@ public final class BuildLanguageOptions extends OptionsBase {
 
  @Option(
  name = "incompatible_no_implicit_watch_label",
- defaultValue = "false",
+ defaultValue = "true",
  documentationCategory = OptionDocumentationCategory.STARLARK_SEMANTICS,
  metadataTags = OptionMetadataTag.INCOMPATIBLE_CHANGE,
  effectTags = OptionEffectTag.LOADING_AND_ANALYSIS,
@@ -963,7 +963,7 @@ public StarlarkSemantics toStarlarkSemantics() {
  public static final String EXPERIMENTAL_ISOLATED_EXTENSION_USAGES =
  "-experimental_isolated_extension_usages";
  public static final String INCOMPATIBLE_NO_IMPLICIT_WATCH_LABEL =
- "-incompatible_no_implicit_watch_label";
+ "+incompatible_no_implicit_watch_label";
  public static final String EXPERIMENTAL_GOOGLE_LEGACY_API = "-experimental_google_legacy_api";
  public static final String EXPERIMENTAL_PLATFORMS_API = "-experimental_platforms_api";
  public static final String EXPERIMENTAL_REPO_REMOTE_EXEC = "-experimental_repo_remote_exec";

src/test/java/com/google/devtools/build/lib/bazel/repository/starlark/StarlarkRepositoryContextTest.java

@@ -516,7 +516,11 @@ public void testWorkspaceRoot() throws Exception {
 
  @Test
  public void testNoIncompatibleNoImplicitWatchLabel() throws Exception {
- setUpContextForRule("test");
+ setUpContextForRule(
+ "test",
+ StarlarkSemantics.DEFAULT.toBuilder()
+ .setBool(BuildLanguageOptions.INCOMPATIBLE_NO_IMPLICIT_WATCH_LABEL, false)
+ .build());
  scratch.file(root.getRelative("foo").getPathString());
  StarlarkPath unusedPath = context.getPath(fakeFileLabel);
  String unusedRead = context.readFile(fakeFileLabel, "no", thread);