3 files changed, 23 insertions, 7 deletions
diff --git a/src/test/java/com/google/devtools/build/lib/packages/util/Crosstool.java b/src/test/java/com/google/devtools/build/lib/packages/util/Crosstool.java
index ddd5b584c9..3642fda958 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/util/Crosstool.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/util/Crosstool.java
@@ -20,6 +20,8 @@ import com.google.protobuf.TextFormat;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 /**
  * A helper class to create a crosstool package containing a CROSSTOOL file, and the various
@@ -111,9 +113,15 @@ final class Crosstool {
         CrosstoolConfig.CrosstoolRelease.newBuilder();
     TextFormat.merge(crosstoolFileContents, configBuilder);
     StringBuilder compilerMap = new StringBuilder();
+    // Remove duplicates
+    Set<String> keys = new LinkedHashSet<>();
     for (CrosstoolConfig.CToolchain toolchain : configBuilder.build().getToolchainList()) {
-      compilerMap.append(String.format("'%s|%s': ':cc-compiler-%s',\n",
-          toolchain.getTargetCpu(), toolchain.getCompiler(), toolchain.getTargetCpu()));
+      String key = String.format("%s|%s", toolchain.getTargetCpu(), toolchain.getCompiler());
+      if (!keys.contains(key)) {
+        keys.add(key);
+        compilerMap.append(
+            String.format("'%s': ':cc-compiler-%s',\n", key, toolchain.getTargetCpu()));
+      }
     }
 
     for (String arch : archs) {
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
index a3251da4f3..ff5940a95e 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/EvaluationTest.java
@@ -359,6 +359,19 @@ public class EvaluationTest extends EvaluationTestCase {
   }
 
   @Test
+  public void testDictWithDuplicatedKey() throws Exception {
+    new SkylarkTest("--incompatible_dict_literal_has_no_duplicates=true")
+        .testIfErrorContains(
+            "Duplicated key \"str\" when creating dictionary", "{'str': 1, 'x': 2, 'str': 3}");
+  }
+
+  @Test
+  public void testDictAllowDuplicatedKey() throws Exception {
+    new SkylarkTest("--incompatible_dict_literal_has_no_duplicates=false")
+        .testStatement("{'str': 1, 'x': 2, 'str': 3}", ImmutableMap.of("str", 3, "x", 2));
+  }
+
+  @Test
   public void testRecursiveTupleDestructuring() throws Exception {
     newTest()
         .setUp("((a, b), (c, d)) = [(1, 2), (3, 4)]")
diff --git a/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java b/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
index 6b93e7e938..a76bbc6847 100644
--- a/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
+++ b/src/test/java/com/google/devtools/build/lib/syntax/MethodLibraryTest.java
@@ -1122,11 +1122,6 @@ public class MethodLibraryTest extends EvaluationTestCase {
   }
 
   @Test
-  public void testDictionaryWithMultipleKeys() throws Exception {
-    new BothModesTest().testStatement("{0: 'a', 1: 'b', 0: 'c'}[0]", "c");
-  }
-
-  @Test
   public void testDictionaryKeyNotFound() throws Exception {
     new BothModesTest()
         .testIfErrorContains("key \"0\" not found in dictionary", "{}['0']")