Merge remote-tracking branch 'origin/swift-4.0-branch' into stable
diff --git a/test/lit.common.cfg b/test/lit.common.cfg
index d8abf4e..e90d738 100644
--- a/test/lit.common.cfg
+++ b/test/lit.common.cfg
@@ -129,10 +129,11 @@
 lit.util.usePlatformSdkOnDarwin(config, lit_config)
 
 if config.host_os == 'Darwin':
+  osx_version = (10, 0, 0)
   try:
     osx_version = subprocess.check_output(["sw_vers", "-productVersion"])
     osx_version = tuple(int(x) for x in osx_version.split('.'))
-    config.darwin_osx_version = osx_version
+    if len(osx_version) == 2: osx_version = (osx_version[0], osx_version[1], 0)
     if osx_version >= (10, 11):
       config.available_features.add('osx-autointerception')
       config.available_features.add('osx-ld64-live_support')
@@ -145,6 +146,8 @@
   except:
     pass
 
+  config.darwin_osx_version = osx_version
+
   # Detect x86_64h
   try:
     output = subprocess.check_output(["sysctl", "hw.cpusubtype"])