#=ERROR showing exception stack=# - What to do?

Hi all,

I’m working on a feature and I’ve gotten to a stage where almost anything I do is giving me the following error:

ODAEProblem Test: Error During Test at /home/alex/.julia/packages/SafeTestsets/A83XK/src/SafeTestsets.jl:25
  Got exception outside of a @test
  #=ERROR showing exception stack=# of type UndefVarError
Test Summary:    | Error  Total     Time
ODAEProblem Test |     1      1  2m04.5s
ERROR: LoadError: Some tests did not pass: 0 passed, 0 failed, 1 errored, 0 broken.
in expression starting at /home/alex/.julia/dev/ModelingToolkit.jl/test/runtests.jl:3
ERROR: Package ModelingToolkit errored during testing

I don’t know what’s going on here, and there’s not much to go on. I’ve resorted to leaving println breadcrumbs throughout the expected callstack which is helping a bit, but what I really want to do is find the root cause of this problem - but I have no idea how I would go about producing an MWE for this.

This looks like a bug in Julia itself, which is concerning to me.

How can I diagnose what’s going on?