Test failures when running tests in parallel creates odd messages

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.


Thanks for reporting this! No worries about the lack of detail – like you point out, this is an opportunity for other people who might also be experiencing this to chime in.

My first stab at a Rails 6 project included this same thing. I had no idea what was causing it. A friend suggested to turn off parallel testing for the first run – which worked – and then I could turn it back on. /shrug???

RSpec, as of April 1, was not yet supporting parallel testing. It apparently requires changes to RSpec-core