Bug 903034 - Fix b2g desktop mochitest regression, r=jgriffin

testing/mochitest/runtests.py

@@ -176,7 +176,15 @@ class MochitestUtilsMixin(object):
 
   def __init__(self):
     os.chdir(SCRIPT_DIR)
-    mozinfo.find_and_update_from_json(SCRIPT_DIR)
+    path = SCRIPT_DIR
+    dirs = []
+    while path != os.path.expanduser('~'):
+        if path in dirs:
+            break
+        dirs.append(path)
+        path = os.path.split(path)[0]
+
+    mozinfo.find_and_update_from_json(*dirs)
 
   def getFullPath(self, path):
     " Get an absolute path relative to self.oldcwd."