Quote from JDK-8277359

[...] add diagnostic information to the test run for the use of JibArtifactManager for resolving the NSS artifact. Capture a before time value and an after time value and report that delta on the test's stdout. For cases where JibArtifactManager eventually gets the job done, we'll have some indication that the slowness of the test is due to JibArtifactManager and not the test itself. Of course, if JibArtifactManager times out, then we should make sure that is reported clearly.