Test and fix with --experimental_sibling_repository_layout

src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java

@@ -216,9 +216,9 @@ private static <T> int build(
         // Create an empty directory and its parent directories but don't visit the TreeArtifact
         // input itself: A TreeArtifact's metadata has type REGULAR_FILE, not DIRECTORY, and would
         // thus lead to an empty file being created in the buildFromActionInputs visitor.
-        DirectoryNode emptyDir = new DirectoryNode(artifact.getExecPath().getBaseName());
-        tree.put(artifact.getExecPath(), emptyDir);
-        createParentDirectoriesIfNotExist(artifact.getExecPath(), emptyDir, tree);
+        DirectoryNode emptyDir = new DirectoryNode(path.getBaseName());
+        tree.put(path, emptyDir);
+        createParentDirectoriesIfNotExist(path, emptyDir, tree);
         continue;
       }
 

src/test/shell/bazel/remote/remote_execution_test.sh

@@ -3110,6 +3110,13 @@ EOF
     --remote_executor=grpc://localhost:${worker_port} \
     --experimental_remote_merkle_tree_cache \
     //pkg:a &>$TEST_log || fail "expected build to succeed with Merkle tree cache"
+
+  bazel clean --expunge
+  bazel build \
+    --spawn_strategy=remote \
+    --remote_executor=grpc://localhost:${worker_port} \
+    --experimental_sibling_repository_layout \
+    //pkg:a &>$TEST_log || fail "expected build to succeed with sibling repository layout"
 }
 
 # Runs coverage with `cc_test` and RE then checks the coverage file is returned.