cros_sdk: turn off pid ns by default

Looks like ccache makes bad assumptions about pid #'s being globally
unique, so turn of pid ns until we can fix that.

BUG=chromium:411984
TEST=`cros_sdk -- ps aux` shows no pid ns being used
TEST=bots don't blow up

Change-Id: I0d729e5fb5e52a898100c3cf288083a8d35ffd45
Reviewed-on: https://chromium-review.googlesource.com/217754
Reviewed-by: David James <davidjames@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/cros_sdk.py b/scripts/cros_sdk.py
index 0ec47a7..9498d99 100644
--- a/scripts/cros_sdk.py
+++ b/scripts/cros_sdk.py
@@ -591,8 +591,10 @@
   group.add_option('--proxy-sim', action='store_true', default=False,
                    help='Simulate a restrictive network requiring an outbound'
                         ' proxy.')
+  # TODO(vapier): Turn off pid ns until ccache issues can be fixed.
+  # http://crbug.com/411984
   group.add_option('--no-ns-pid', dest='ns_pid',
-                   default=True, action='store_false',
+                   default=False, action='store_false',
                    help='Do not create a new PID namespace.')
 
   # Internal options.