Fix glob in bower2bazel.py

This fixes I850271bb1c657a5ffe77946a6beaf54a3680af75.

Change-Id: I128ae1b88adc267b0f1f9b1db7b0a96a87a861b3

tools/js/bower2bazel.py

diff --git a/tools/js/bower2bazel.py b/tools/js/bower2bazel.py
index ea0402c..2114de7 100755
--- a/tools/js/bower2bazel.py
+++ b/tools/js/bower2bazel.py
@@ -77,11 +77,10 @@
 
   seeds = set(seeds)
   for v in version_targets:
-    try:
-      fn = os.path.join("bazel-out/local-fastbuild/bin", v.lstrip("/").replace(":", "/"))
-    except:
-      fn = os.path.join("bazel-out/darwin_x86_64-fastbuild/bin", v.lstrip("/").replace(":", "/"))
-    with open(fn) as f:
+    path = os.path.join("bazel-out/*-fastbuild/bin", v.lstrip("/").replace(":", "/"))
+    fs = glob.glob(path)
+    assert len(fs) == 1, '%s: file not found or multiple files found: %s' % (path, fs)
+    with open(fs[0]) as f:
       j = json.load(f)
       if "" in j:
         # drop dummy entries.