I spent a good portion of last week writing up thoughts on how to improve my prototype motrfile, before I start moving more stuff into MOTR proper.
Today, I put some of those notes into practice, which was mainly focused on putting together a wrapper around the virtualenv package to replace the wrapper around the stdlib venv module. This is mainly important because I want to support multi-version testing, and specifically pypy2. I haven't looked at all into how to attain the speed benefits that are supposed to be possible.
Where I'm at now is, I have a basic implementation of the virtualenv wrapper, more-or-less according to my notes. Now, I need to kind of iterate on things until I'm using a proper combination of virtualenv and pyproject-build, at which point I should be able to ditch the wrappers for venv and Flit. Actually getting there will be interesting, because I'm going to want to write actions for generating configuration files for pytest and coverage.py. (And later, mypy, I think, once I have mutation testing.)
Anyway, I think carrying this out is going to take another high-level look at the code.
Which is going to happen tomorrow, not tonight, because I am exhausted.