Oscar Smith

@ChrisRackauckas I think your merge was wrong. I'll fix it.

I think I can make this work without requiring a DelayDiffEq fix (`current` just needs to initialize to 0). https://github.com/SciML/OrdinaryDiffEq.jl/pull/2185 has all the changes needed for this to be used...

Unfortunately the fully grounded approach makes this type of test impossible. I think the only thing we can test is that the number of steps and f evals roughly match...

I think this now all works.

we could, but I'm not sure that's the best test. figuring out appropriate error levels there is always a little ad hoc, and I'm this case, we know exactly what...

I believe this is now ready to merge.

This I believe does all the things that PR requires. Specifically, it is type stable, and roughly the same for precompile. I'm not sure either version actually makes a significant...

The test failure was from me being wrong about which algorithm would be used for exrober at the last timestep. (I think due to the same issue that causes https://github.com/SciML/OrdinaryDiffEq.jl/issues/2198)....

The DelayDiffEq failures seem real (although the tests that are failing do seem pretty bad)

Re-running CI (now that it's morning so codecov will hopefully be happier and now that the OrdinaryDiffEq test that I think was the only real failure is fixed).