diff --git a/src/test/java/com/google/devtools/build/lib/BUILD b/src/test/java/com/google/devtools/build/lib/BUILD
index 4b40fcc..ee164fe 100644
--- a/src/test/java/com/google/devtools/build/lib/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/BUILD
@@ -470,6 +470,7 @@
         "//src/test/java/com/google/devtools/build/skyframe:testutil",
         "//third_party:auto_value",
         "//third_party:guava",
+        "//third_party:mockito",
         "//third_party:truth",
     ],
 )
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
index 43b2733..decc03e 100644
--- a/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
+++ b/src/test/java/com/google/devtools/build/lib/analysis/util/AnalysisMock.java
@@ -34,6 +34,7 @@
 import com.google.devtools.build.lib.rules.repository.RepositoryDelegatorFunction;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
 import com.google.devtools.build.lib.rules.repository.RepositoryLoaderFunction;
+import com.google.devtools.build.lib.skyframe.BazelSkyframeExecutorConstants;
 import com.google.devtools.build.lib.skyframe.SkyFunctions;
 import com.google.devtools.build.lib.skyframe.packages.PackageFactoryBuilderWithSkyframeForTesting;
 import com.google.devtools.build.lib.testutil.TestConstants;
@@ -132,7 +133,8 @@
             new AtomicBoolean(true),
             ImmutableMap::of,
             directories,
-            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES),
+            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER),
         SkyFunctions.REPOSITORY,
         new RepositoryLoaderFunction(),
         CcSkyframeFdoSupportValue.SKYFUNCTION,
diff --git a/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java
index 94be36d..1143a26 100644
--- a/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkRepositoryIntegrationTest.java
@@ -33,6 +33,7 @@
 import com.google.devtools.build.lib.rules.repository.RepositoryDelegatorFunction;
 import com.google.devtools.build.lib.rules.repository.RepositoryFunction;
 import com.google.devtools.build.lib.rules.repository.RepositoryLoaderFunction;
+import com.google.devtools.build.lib.skyframe.BazelSkyframeExecutorConstants;
 import com.google.devtools.build.lib.skyframe.ConfiguredTargetAndData;
 import com.google.devtools.build.lib.skyframe.SkyFunctions;
 import com.google.devtools.build.lib.skylarkbuildapi.repository.RepositoryBootstrap;
@@ -85,7 +86,8 @@
               new AtomicBoolean(true),
               ImmutableMap::of,
               directories,
-              ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES);
+              ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES,
+              BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER);
       return ImmutableMap.of(
           SkyFunctions.REPOSITORY_DIRECTORY,
           function,
diff --git a/src/test/java/com/google/devtools/build/lib/repository/ExternalPackageUtilTest.java b/src/test/java/com/google/devtools/build/lib/repository/ExternalPackageHelperTest.java
similarity index 71%
rename from src/test/java/com/google/devtools/build/lib/repository/ExternalPackageUtilTest.java
rename to src/test/java/com/google/devtools/build/lib/repository/ExternalPackageHelperTest.java
index 6476dfb..55a936f 100644
--- a/src/test/java/com/google/devtools/build/lib/repository/ExternalPackageUtilTest.java
+++ b/src/test/java/com/google/devtools/build/lib/repository/ExternalPackageHelperTest.java
@@ -16,6 +16,8 @@
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.devtools.build.skyframe.EvaluationResultSubjectFactory.assertThatEvaluationResult;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 import com.google.auto.value.AutoValue;
 import com.google.common.base.Optional;
@@ -29,6 +31,7 @@
 import com.google.devtools.build.lib.analysis.util.BuildViewTestCase;
 import com.google.devtools.build.lib.cmdline.PackageIdentifier;
 import com.google.devtools.build.lib.events.NullEventHandler;
+import com.google.devtools.build.lib.packages.BuildFileName;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.RuleClassProvider;
 import com.google.devtools.build.lib.packages.WorkspaceFileValue;
@@ -53,6 +56,7 @@
 import com.google.devtools.build.lib.skyframe.WorkspaceFileFunction;
 import com.google.devtools.build.lib.syntax.StarlarkSemantics;
 import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
+import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.Root;
 import com.google.devtools.build.lib.vfs.RootedPath;
 import com.google.devtools.build.lib.vfs.UnixGlob;
@@ -65,6 +69,7 @@
 import com.google.devtools.build.skyframe.SequencedRecordingDifferencer;
 import com.google.devtools.build.skyframe.SequentialBuildDriver;
 import com.google.devtools.build.skyframe.SkyFunction;
+import com.google.devtools.build.skyframe.SkyFunction.Environment;
 import com.google.devtools.build.skyframe.SkyFunctionException;
 import com.google.devtools.build.skyframe.SkyFunctionName;
 import com.google.devtools.build.skyframe.SkyKey;
@@ -79,9 +84,17 @@
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;
 
-/** Unit tests for {@link ExternalPackageUtil}. */
+/** Unit tests for {@link ExternalPackageHelper}. */
 @RunWith(JUnit4.class)
-public class ExternalPackageUtilTest extends BuildViewTestCase {
+public class ExternalPackageHelperTest extends BuildViewTestCase {
+  private static final Root MOCK_ROOT = mockRoot();
+
+  private static Root mockRoot() {
+    Root root = mock(Root.class);
+    when(root.isAbsolute()).thenReturn(false);
+    return root;
+  }
+
   private static final EvaluationContext EVALUATION_OPTIONS =
       EvaluationContext.newBuilder()
           .setKeepGoing(false)
@@ -120,7 +133,8 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         FileStateValue.FILE_STATE,
         new FileStateFunction(
@@ -140,9 +154,22 @@
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
     skyFunctions.put(
-        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+        SkyFunctions.PACKAGE,
+        new PackageFunction(
+            null,
+            null,
+            null,
+            null,
+            null,
+            null,
+            null,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
 
     // Helper Skyfunctions to call ExternalPackageUtil.
     skyFunctions.put(GET_RULE_BY_NAME_FUNCTION, new GetRuleByNameFunction());
@@ -198,24 +225,72 @@
   }
 
   @Test
-  public void getRegisteredToolchains() throws Exception {
+  public void getRegisteredToolchains_addedInWorkspace() throws Exception {
     scratch.overwriteFile(
         "WORKSPACE", "register_toolchains(", "  '//toolchain:tc1',", "  '//toolchain:tc2')");
 
-    SkyKey key = getRegisteredToolchainsKey();
-    EvaluationResult<GetRegisteredToolchainsValue> result = getRegisteredToolchains(key);
-
-    assertThatEvaluationResult(result).hasNoError();
-
-    assertThat(result.get(key).registeredToolchains())
+    assertThat(getRegisteredToolchains())
         // There are default toolchains that are always registered, so just check for the ones added
         .containsAtLeast("//toolchain:tc1", "//toolchain:tc2")
         .inOrder();
   }
 
-  EvaluationResult<GetRegisteredToolchainsValue> getRegisteredToolchains(SkyKey key)
-      throws InterruptedException {
-    return driver.<GetRegisteredToolchainsValue>evaluate(ImmutableList.of(key), EVALUATION_OPTIONS);
+  @Test
+  public void getRegisteredToolchains_workspaceBazelPreferred() throws Exception {
+    scratch.overwriteFile("WORKSPACE", "register_toolchains('//toolchain:WORKSPACE')");
+    scratch.overwriteFile("WORKSPACE.bazel", "register_toolchains('//toolchain:WORKSPACE_bazel')");
+
+    getRegisteredToolchains();
+    ImmutableList<String> registeredToolchains = getRegisteredToolchains();
+
+    assertThat(registeredToolchains).contains("//toolchain:WORKSPACE_bazel");
+    assertThat(registeredToolchains).doesNotContain("//toolchain:WORKSPACE");
+  }
+
+  @Test
+  public void getRegisteredToolchains_workspaceBazelNotAFile() throws Exception {
+    scratch.overwriteFile("WORKSPACE", "register_toolchains('//toolchain:WORKSPACE')");
+    scratch.dir("WORKSPACE.bazel");
+
+    getRegisteredToolchains();
+    ImmutableList<String> registeredToolchains = getRegisteredToolchains();
+
+    assertThat(registeredToolchains).contains("//toolchain:WORKSPACE");
+  }
+
+  @Test
+  public void findWorkspaceFile_firstIsFile() throws Exception {
+    ExternalPackageHelper helper =
+        new ExternalPackageHelper(
+            ImmutableList.of(BuildFileName.WORKSPACE, BuildFileName.WORKSPACE_DOT_BAZEL));
+    Environment env = createMockEnvironment();
+    mockFileValue(env, BuildFileName.WORKSPACE, /*isFile=*/ true);
+
+    assertThat(helper.findWorkspaceFile(env)).isEqualTo(rootedPath(BuildFileName.WORKSPACE));
+  }
+
+  @Test
+  public void findWorkspaceFile_firstNotAFileFallbackToSecond() throws Exception {
+    ExternalPackageHelper helper =
+        new ExternalPackageHelper(
+            ImmutableList.of(BuildFileName.WORKSPACE_DOT_BAZEL, BuildFileName.WORKSPACE));
+    Environment env = createMockEnvironment();
+    mockFileValue(env, BuildFileName.WORKSPACE_DOT_BAZEL, /*isFile=*/ false);
+    mockFileValue(env, BuildFileName.WORKSPACE, /*isFile=*/ true);
+
+    assertThat(helper.findWorkspaceFile(env)).isEqualTo(rootedPath(BuildFileName.WORKSPACE));
+  }
+
+  @Test
+  public void findWorkspaceFile_noneAreFilesReturnLast() throws Exception {
+    ExternalPackageHelper helper =
+        new ExternalPackageHelper(
+            ImmutableList.of(BuildFileName.WORKSPACE_DOT_BAZEL, BuildFileName.WORKSPACE));
+    Environment env = createMockEnvironment();
+    mockFileValue(env, BuildFileName.WORKSPACE_DOT_BAZEL, /*isFile=*/ false);
+    mockFileValue(env, BuildFileName.WORKSPACE, /*isFile=*/ false);
+
+    assertThat(helper.findWorkspaceFile(env)).isEqualTo(rootedPath(BuildFileName.WORKSPACE));
   }
 
   @Test
@@ -223,7 +298,7 @@
     scratch.overwriteFile(
         "WORKSPACE", "register_execution_platforms(", "  '//platform:ep1',", "  '//platform:ep2')");
 
-    SkyKey key = getRegisteredExecutionPlatformsKey();
+    SkyKey key = () -> GET_REGISTERED_EXECUTION_PLATFORMS_FUNCTION;
     EvaluationResult<GetRegisteredExecutionPlatformsValue> result =
         getRegisteredExecutionPlatforms(key);
 
@@ -242,6 +317,36 @@
 
   // HELPER SKYFUNCTIONS
 
+  private static Environment createMockEnvironment() throws InterruptedException {
+    Environment env = mock(Environment.class);
+    when(env.getValue(PrecomputedValue.PATH_PACKAGE_LOCATOR.getKeyForTesting()))
+        .thenReturn(
+            new PrecomputedValue(
+                new PathPackageLocator(
+                    mock(Path.class), ImmutableList.of(MOCK_ROOT), ImmutableList.of())));
+    return env;
+  }
+
+  private static void mockFileValue(Environment env, BuildFileName buildFileName, boolean isFile)
+      throws InterruptedException {
+    FileValue fileValue = mock(FileValue.class);
+    when(fileValue.isFile()).thenReturn(isFile);
+    when(env.getValue(FileValue.key(rootedPath(buildFileName)))).thenReturn(fileValue);
+  }
+
+  private static RootedPath rootedPath(BuildFileName buildFileName) {
+    return RootedPath.toRootedPath(MOCK_ROOT, buildFileName.getFilenameFragment());
+  }
+
+  private ImmutableList<String> getRegisteredToolchains() throws InterruptedException {
+    SkyKey key = getRegisteredToolchainsKey();
+    EvaluationResult<GetRegisteredToolchainsValue> result =
+        driver.evaluate(ImmutableList.of(key), EVALUATION_OPTIONS);
+
+    assertThatEvaluationResult(result).hasNoError();
+    return result.get(key).registeredToolchains();
+  }
+
   // GetRuleByName.
   private static SkyKey getRuleByNameKey(String ruleName) {
     return new Key(ruleName);
@@ -255,7 +360,7 @@
     abstract Rule rule();
 
     static GetRuleByNameValue create(Rule rule) {
-      return new AutoValue_ExternalPackageUtilTest_GetRuleByNameValue(rule);
+      return new AutoValue_ExternalPackageHelperTest_GetRuleByNameValue(rule);
     }
   }
 
@@ -267,7 +372,8 @@
         throws SkyFunctionException, InterruptedException {
       String ruleName = (String) skyKey.argument();
 
-      Rule rule = ExternalPackageUtil.getRuleByName(ruleName, env);
+      Rule rule =
+          BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER.getRuleByName(ruleName, env);
       if (rule == null) {
         return null;
       }
@@ -294,7 +400,7 @@
     abstract ImmutableList<String> registeredToolchains();
 
     static GetRegisteredToolchainsValue create(Iterable<String> registeredToolchains) {
-      return new AutoValue_ExternalPackageUtilTest_GetRegisteredToolchainsValue(
+      return new AutoValue_ExternalPackageHelperTest_GetRegisteredToolchainsValue(
           ImmutableList.copyOf(registeredToolchains));
     }
   }
@@ -319,11 +425,6 @@
     }
   }
 
-  // GetRegisteredExecutionPlatforms.
-  private static SkyKey getRegisteredExecutionPlatformsKey() {
-    return () -> GET_REGISTERED_EXECUTION_PLATFORMS_FUNCTION;
-  }
-
   private static final SkyFunctionName GET_REGISTERED_EXECUTION_PLATFORMS_FUNCTION =
       SkyFunctionName.createHermetic("GET_REGISTERED_EXECUTION_PLATFORMS_FUNCTION");
 
@@ -333,7 +434,7 @@
 
     static GetRegisteredExecutionPlatformsValue create(
         Iterable<String> registeredExecutionPlatforms) {
-      return new AutoValue_ExternalPackageUtilTest_GetRegisteredExecutionPlatformsValue(
+      return new AutoValue_ExternalPackageHelperTest_GetRegisteredExecutionPlatformsValue(
           ImmutableList.copyOf(registeredExecutionPlatforms));
     }
   }
diff --git a/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorTest.java b/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorTest.java
index 8ebc7f1..4055ddd 100644
--- a/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorTest.java
+++ b/src/test/java/com/google/devtools/build/lib/rules/repository/RepositoryDelegatorTest.java
@@ -130,7 +130,8 @@
             new AtomicBoolean(true),
             ImmutableMap::of,
             directories,
-            managedDirectoriesKnowledge);
+            managedDirectoriesKnowledge,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER);
     AtomicReference<PathPackageLocator> pkgLocator =
         new AtomicReference<>(
             new PathPackageLocator(
@@ -172,13 +173,14 @@
                 .put(SkyFunctions.REPOSITORY_DIRECTORY, delegatorFunction)
                 .put(
                     SkyFunctions.PACKAGE,
-                    new PackageFunction(null, null, null, null, null, null, null))
+                    new PackageFunction(null, null, null, null, null, null, null, null))
                 .put(
                     SkyFunctions.PACKAGE_LOOKUP,
                     new PackageLookupFunction(
                         new AtomicReference<>(ImmutableSet.of()),
                         CrossRepositoryLabelViolationStrategy.ERROR,
-                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY))
+                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(SkyFunctions.WORKSPACE_AST, new WorkspaceASTFunction(ruleClassProvider))
                 .put(
                     WorkspaceFileValue.WORKSPACE_FILE,
@@ -190,8 +192,14 @@
                         directories,
                         starlarkImportLookupFunction))
                 .put(SkyFunctions.REPOSITORY, new RepositoryLoaderFunction())
-                .put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction())
-                .put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction())
+                .put(
+                    SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+                    new LocalRepositoryLookupFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
+                .put(
+                    SkyFunctions.EXTERNAL_PACKAGE,
+                    new ExternalPackageFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(SkyFunctions.PRECOMPUTED, new PrecomputedFunction())
                 .put(SkyFunctions.AST_FILE_LOOKUP, new ASTFileLookupFunction(ruleClassProvider))
                 .put(SkyFunctions.CONTAINING_PACKAGE_LOOKUP, new ContainingPackageLookupFunction())
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTestCase.java b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTestCase.java
index 51a339f..95472e0 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTestCase.java
@@ -88,10 +88,12 @@
             root,
             /* defaultSystemJavabase= */ null,
             TestConstants.PRODUCT_NAME);
-    ExternalFilesHelper externalFilesHelper = ExternalFilesHelper.createForTesting(
-        pkgLocator,
-        ExternalFileAction.DEPEND_ON_EXTERNAL_PKG_FOR_EXTERNAL_REPO_PATHS,
-        directories);
+    ExternalFilesHelper externalFilesHelper =
+        ExternalFilesHelper.createForTesting(
+            pkgLocator,
+            ExternalFileAction.DEPEND_ON_EXTERNAL_PKG_FOR_EXTERNAL_REPO_PATHS,
+            directories,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER);
     differencer = new SequencedRecordingDifferencer();
     evaluator =
         new InMemoryMemoizingEvaluator(
@@ -107,13 +109,14 @@
                 .put(SkyFunctions.ACTION_EXECUTION, new SimpleActionExecutionFunction())
                 .put(
                     SkyFunctions.PACKAGE,
-                    new PackageFunction(null, null, null, null, null, null, null))
+                    new PackageFunction(null, null, null, null, null, null, null, null))
                 .put(
                     SkyFunctions.PACKAGE_LOOKUP,
                     new PackageLookupFunction(
                         null,
                         CrossRepositoryLabelViolationStrategy.ERROR,
-                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY))
+                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(
                     SkyFunctions.WORKSPACE_AST,
                     new WorkspaceASTFunction(TestRuleClassProvider.getRuleClassProvider()))
@@ -126,7 +129,10 @@
                             .build(TestRuleClassProvider.getRuleClassProvider(), fs),
                         directories,
                         /*starlarkImportLookupFunctionForInlining=*/ null))
-                .put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction())
+                .put(
+                    SkyFunctions.EXTERNAL_PACKAGE,
+                    new ExternalPackageFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(
                     SkyFunctions.ACTION_TEMPLATE_EXPANSION,
                     new ActionTemplateExpansionFunction(actionKeyContext))
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/ContainingPackageLookupFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/ContainingPackageLookupFunctionTest.java
index a89220b..5cd51aa 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/ContainingPackageLookupFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/ContainingPackageLookupFunctionTest.java
@@ -110,9 +110,10 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
-        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null));
+        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null, null));
     skyFunctions.put(
         SkyFunctions.BLACKLISTED_PACKAGE_PREFIXES,
         new BlacklistedPackagePrefixesFunction(
@@ -140,8 +141,12 @@
                 .build(ruleClassProvider, fileSystem),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.FILE_SYMLINK_CYCLE_UNIQUENESS, new FileSymlinkCycleUniquenessFunction());
     ImmutableMap<String, RepositoryFunction> repositoryHandlers =
@@ -155,7 +160,8 @@
             new AtomicBoolean(true),
             ImmutableMap::of,
             directories,
-            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES));
+            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(SkyFunctions.REPOSITORY, new RepositoryLoaderFunction());
 
     differencer = new SequencedRecordingDifferencer();
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FileFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FileFunctionTest.java
index 4f15eb2..b8badae 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FileFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FileFunctionTest.java
@@ -174,13 +174,14 @@
                 .put(FileValue.FILE, new FileFunction(pkgLocatorRef))
                 .put(
                     SkyFunctions.PACKAGE,
-                    new PackageFunction(null, null, null, null, null, null, null))
+                    new PackageFunction(null, null, null, null, null, null, null, null))
                 .put(
                     SkyFunctions.PACKAGE_LOOKUP,
                     new PackageLookupFunction(
                         new AtomicReference<>(ImmutableSet.of()),
                         CrossRepositoryLabelViolationStrategy.ERROR,
-                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY))
+                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(SkyFunctions.WORKSPACE_AST, new WorkspaceASTFunction(ruleClassProvider))
                 .put(
                     WorkspaceFileValue.WORKSPACE_FILE,
@@ -191,8 +192,14 @@
                             .build(ruleClassProvider, fs),
                         directories,
                         /*starlarkImportLookupFunctionForInlining=*/ null))
-                .put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction())
-                .put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction())
+                .put(
+                    SkyFunctions.EXTERNAL_PACKAGE,
+                    new ExternalPackageFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
+                .put(
+                    SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+                    new LocalRepositoryLookupFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .build(),
             differencer);
     PrecomputedValue.BUILD_ID.set(differencer, UUID.randomUUID());
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
index 60fd338..bebd3f5 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FilesetEntryFunctionTest.java
@@ -125,7 +125,8 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.BLACKLISTED_PACKAGE_PREFIXES,
         new BlacklistedPackagePrefixesFunction(
@@ -133,7 +134,9 @@
     skyFunctions.put(
         SkyFunctions.FILESET_ENTRY, new FilesetEntryFunction((unused) -> rootDirectory));
     skyFunctions.put(SkyFunctions.WORKSPACE_NAME, new TestWorkspaceNameFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
 
     differencer = new SequencedRecordingDifferencer();
     evaluator = new InMemoryMemoizingEvaluator(skyFunctions, differencer);
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
index f7e1c21..f9ebf7f 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/FilesystemValueCheckerTest.java
@@ -152,14 +152,15 @@
     skyFunctions.put(
         SkyFunctions.FILE_SYMLINK_INFINITE_EXPANSION_UNIQUENESS,
         new FileSymlinkInfiniteExpansionUniquenessFunction());
-    skyFunctions.put(SkyFunctions.PACKAGE,
-        new PackageFunction(null, null, null, null, null, null, null));
+    skyFunctions.put(
+        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null, null));
     skyFunctions.put(
         SkyFunctions.PACKAGE_LOOKUP,
         new PackageLookupFunction(
             new AtomicReference<>(ImmutableSet.<PackageIdentifier>of()),
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(SkyFunctions.WORKSPACE_AST,
         new WorkspaceASTFunction(TestRuleClassProvider.getRuleClassProvider()));
     skyFunctions.put(
@@ -171,7 +172,9 @@
                 .build(TestRuleClassProvider.getRuleClassProvider(), fs),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
 
     differencer = new SequencedRecordingDifferencer();
     evaluator = new InMemoryMemoizingEvaluator(skyFunctions.build(), differencer);
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/GlobFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/GlobFunctionTest.java
index c245ae4..9ce1d92 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/GlobFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/GlobFunctionTest.java
@@ -169,7 +169,8 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.BLACKLISTED_PACKAGE_PREFIXES,
         BazelSkyframeExecutorConstants.BLACKLISTED_PACKAGE_PREFIXES_FUNCTION);
@@ -198,8 +199,12 @@
                 .build(ruleClassProvider, fs),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     return skyFunctions;
   }
 
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/LocalRepositoryLookupFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/LocalRepositoryLookupFunctionTest.java
index 6505635..dcf4a09 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/LocalRepositoryLookupFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/LocalRepositoryLookupFunctionTest.java
@@ -93,7 +93,8 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         FileStateValue.FILE_STATE,
         new FileStateFunction(
@@ -117,8 +118,12 @@
                 .build(ruleClassProvider, fileSystem),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.FILE_SYMLINK_CYCLE_UNIQUENESS, new FileSymlinkCycleUniquenessFunction());
 
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/PackageLookupFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/PackageLookupFunctionTest.java
index 19c7632..e297fc8 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/PackageLookupFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/PackageLookupFunctionTest.java
@@ -118,10 +118,10 @@
         new PackageLookupFunction(
             deletedPackages,
             crossRepositoryLabelViolationStrategy(),
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
-        SkyFunctions.PACKAGE,
-        new PackageFunction(null, null, null, null, null, null, null));
+        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null, null));
     skyFunctions.put(
         FileStateValue.FILE_STATE,
         new FileStateFunction(
@@ -149,8 +149,12 @@
                 .build(ruleClassProvider, fileSystem),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.FILE_SYMLINK_CYCLE_UNIQUENESS, new FileSymlinkCycleUniquenessFunction());
 
@@ -165,7 +169,8 @@
             new AtomicBoolean(true),
             ImmutableMap::of,
             directories,
-            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES));
+            ManagedDirectoriesKnowledge.NO_MANAGED_DIRECTORIES,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(SkyFunctions.REPOSITORY, new RepositoryLoaderFunction());
 
     differencer = new SequencedRecordingDifferencer();
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
index f563cc7..74fda80 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/RecursiveFilesystemTraversalFunctionTest.java
@@ -157,13 +157,14 @@
         new PackageLookupFunction(
             deletedPackages,
             CrossRepositoryLabelViolationStrategy.ERROR,
-            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY));
+            BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+            BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.BLACKLISTED_PACKAGE_PREFIXES,
         new BlacklistedPackagePrefixesFunction(
             /*blacklistedPackagePrefixesFile=*/ PathFragment.EMPTY_FRAGMENT));
-    skyFunctions.put(SkyFunctions.PACKAGE,
-        new PackageFunction(null, null, null, null, null, null, null));
+    skyFunctions.put(
+        SkyFunctions.PACKAGE, new PackageFunction(null, null, null, null, null, null, null, null));
     skyFunctions.put(SkyFunctions.WORKSPACE_AST, new WorkspaceASTFunction(ruleClassProvider));
     skyFunctions.put(
         WorkspaceFileValue.WORKSPACE_FILE,
@@ -174,8 +175,12 @@
                 .build(ruleClassProvider, fileSystem),
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null));
-    skyFunctions.put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction());
-    skyFunctions.put(SkyFunctions.LOCAL_REPOSITORY_LOOKUP, new LocalRepositoryLookupFunction());
+    skyFunctions.put(
+        SkyFunctions.EXTERNAL_PACKAGE,
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
+    skyFunctions.put(
+        SkyFunctions.LOCAL_REPOSITORY_LOOKUP,
+        new LocalRepositoryLookupFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER));
     skyFunctions.put(
         SkyFunctions.FILE_SYMLINK_INFINITE_EXPANSION_UNIQUENESS,
         new FileSymlinkInfiniteExpansionUniquenessFunction());
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
index e482577..a7635bb 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderTestCase.java
@@ -246,13 +246,14 @@
                     new ActionExecutionFunction(skyframeActionExecutor, directories, tsgmRef))
                 .put(
                     SkyFunctions.PACKAGE,
-                    new PackageFunction(null, null, null, null, null, null, null))
+                    new PackageFunction(null, null, null, null, null, null, null, null))
                 .put(
                     SkyFunctions.PACKAGE_LOOKUP,
                     new PackageLookupFunction(
                         null,
                         CrossRepositoryLabelViolationStrategy.ERROR,
-                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY))
+                        BazelSkyframeExecutorConstants.BUILD_FILES_BY_PRIORITY,
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(
                     SkyFunctions.WORKSPACE_AST,
                     new WorkspaceASTFunction(TestRuleClassProvider.getRuleClassProvider()))
@@ -265,7 +266,10 @@
                             .build(TestRuleClassProvider.getRuleClassProvider(), fileSystem),
                         directories,
                         /*starlarkImportLookupFunctionForInlining=*/ null))
-                .put(SkyFunctions.EXTERNAL_PACKAGE, new ExternalPackageFunction())
+                .put(
+                    SkyFunctions.EXTERNAL_PACKAGE,
+                    new ExternalPackageFunction(
+                        BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER))
                 .put(
                     SkyFunctions.ACTION_TEMPLATE_EXPANSION,
                     new DelegatingActionTemplateExpansionFunction())
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunctionTest.java
index 31aaddb..a50493e 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunctionTest.java
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceFileFunctionTest.java
@@ -138,7 +138,8 @@
             pkgFactory,
             directories,
             /*starlarkImportLookupFunctionForInlining=*/ null);
-    externalSkyFunc = new ExternalPackageFunction();
+    externalSkyFunc =
+        new ExternalPackageFunction(BazelSkyframeExecutorConstants.EXTERNAL_PACKAGE_HELPER);
     astSkyFunc = new WorkspaceASTFunction(ruleClassProvider);
     fakeWorkspaceFileValue = new FakeFileValue();
   }