In going through the yt4-merge pull request, Kacper and I tracked down some issues related to the changeover in unyt from using reference values in CGS to using reference values in MKS. Rather than attempt to reconcile these two things (ok actually we *tried* but it turns out it's super duper hard, thanks a LOT floating point math) it seems that the simpler thing to do is to make most of the values compared in the base unit system of "code" rather than CGS.
I have issued this pull request:
to change over the default for the answer value tests to use unit_system="code" if the ds is supplied as a string (rather than an object).
Now, if we are concerned that we do not have adequate test coverage for verifying that the units are in CGS, or if we have concerns about this glossing over some CGS conversion factor issues, we should perhaps supplement these tests.
This PR will be ready once all of the test storage IDs have been updated, and once I've migrated most/all of the datasets to using unit_system="code", but I wanted to open this up for possible discussion here. It's entirely possible this is not an acceptable solution, and I am hoping that folks may have some feedback. What am I missing? :)
PS I genuinely think that this might un-clog a whole bunch of issues in the yt4-merge, and we can focus on just verifying the results for the SPH datasets. Hooray!