We can often see in the jrmc test suite that the test testAllCiphers takes approximately 500 seconds to finish. According to Henrik Dafgård, this can happen if the computer has "used up all entropy needed for randomization".

In the test run for JMC 6.0.0-289, we saw this on 64-bit Linux machines.

We don't yet know if this is related to virtual machines or not.