I have noticed that sometimes, when a test fails, instead of seeing the normal test output, I get a massive stack trace involving Drb that goes away when I turn off parallel tests. Next time I get it, I’ll try to post it in here. Sorry it’s scant on details, but maybe someone else experienced this and can post?
This is when using the default rails testing framework. Have not seen it with RSpec, though I don’t know if Rspec uses the parallel testing feature.