Fix ReentrantMutex locking inside Fiber spec for ruby-3.2

[ojab]

It raises ThreadError since ruby/ruby#6680

[ojab]

First-time contributors need a maintainer to approve running workflows.

Sending to review, specs are green locally with ruby-3.2-preview3

[ojab]

Also, should reach here is copypasted from existing spec, shouldn't it be should not reach here?

[pirj]

The old spec didn't fail with ruby 3.2.0dev (2022-10-26T15:29:12Z master fa0adbad92), and it doesn't fail now with ruby 3.2.0dev (2022-11-17T18:58:56Z master 0446d961a0).
The breaking change in Ruby was made between those runs.
We skip sub-builds for ruby-head, so it's not possible to confirm the failure from rspec-mocks build.

I intend to:

• stash the changes temporarily
• reproduce the failure
• get the changes back

[pirj]

A failing 3.2 build 👍

[pirj]

Thank you!

[JonRowe]

Realistically this should be a pending spec on Ruby 3.2 as its something we should look to fix... (Its not expected to error, it just does)...

[eregon]

Looks good to me, this just adapts the test to the new exception/behavior in CRuby

[JonRowe]

I've been working on reworking the spec to run, I don't think its a change in behaviour it's just the way of testing it that broke?

[eregon]

It's a behavior change in Ruby, the deadlock is detected and so it doesn't hang.
I think it's difficult to design a test that works with both and is still readable, so I think this is a good solution.

An alternative would be to use a Fiber scheduler, then it would behave as before, since with a scheduler it makes sense to wait. A Fiber scheduler is probably the reason we needed to fix RSpec ReentrantMutex. Would need to make a dummy Fiber scheduler for tests, it's probably fairly short if only used for this example.

[eregon]

#501 is the original issue

[JonRowe]

I'm closing this for now, we currently skip this on Rubies were its broken, I'd like to fix this spec rather than a no op expect an error (probably needing a fiber scheduler) especially as on my machine its definielty a broken spec (the raise leaks rather than a deadlock)