[bazel] Set CLOSURE_COMPILER to workaround RBE+symlinks issue (#1037)

* [bazel] Set CLOSURE_COMPILER to workaround RBE+symlinks issue

* space

* specify node_js

Author: kjlubick

bazel/emscripten_toolchain/emscripten_config

@@ -3,12 +3,21 @@ import platform
 
 ROOT_DIR = os.environ["ROOT_DIR"]
 EMSCRIPTEN_ROOT = os.environ["EMSCRIPTEN"]
-BINARYEN_ROOT = ROOT_DIR + "/" + os.environ["EM_BIN_PATH"]
-LLVM_ROOT = BINARYEN_ROOT + "/bin"
+BINARYEN_ROOT = os.path.join(ROOT_DIR, os.environ["EM_BIN_PATH"])
+LLVM_ROOT = os.path.join(BINARYEN_ROOT, "bin")
 FROZEN_CACHE = True
 
 system = platform.system()
 
 machine = "arm64" if platform.machine() == "arm64" else "amd64"
 nodejs_binary = "bin/nodejs/node.exe" if(system =="Windows") else "bin/node"
 NODE_JS = ROOT_DIR + "/external/nodejs_{}_{}/{}".format(system.lower(), machine, nodejs_binary)
+
+
+# This works around an issue with Bazel RBE where the symlinks in node_modules/.bin
+# are uploaded as the linked files, which means the cli.js cannot load its
+# dependencies from the expected locations.
+# See https://github.com/emscripten-core/emscripten/pull/16640 for more
+if system != "Windows":
+    CLOSURE_COMPILER = [NODE_JS, os.path.join(EMSCRIPTEN_ROOT, "node_modules",
+                                              "google-closure-compiler", "cli.js")]