Description of the problem / feature request / question:

After running tests, I see this warning:

WARNING: Cannot delete sandbox directory after action execution: /private/var/tmp/_bazel_user/81e2f173210dcd47c26dbf4a42147a8b/bazel-sandbox/2551a3b4-abe3-4c34-a39d-37b44153e291-0 (java.io.IOException: /private/var/tmp/_bazel_user/81e2f173210dcd47c26dbf4a42147a8b/bazel-sandbox/2551a3b4-abe3-4c34-a39d-37b44153e291-0/execroot/master/_tmp/tests_2 (Directory not empty)).

Please let me know how I can provide more debugging information.

Environment info

• Operating System:
  macOS Sierra 10.12.2

• Bazel version (output of bazel info release):
  release 0.4.3-homebrew