The release 1.4 is a switch to Python3. So anyone downloading the script directly from Github may experience problems.
The build system does also take advantage of type checking the code with retype+mypy. Static code analysis is simply better than just relying on a testsuite to cover everything.
The docker-copyedit.py binary does support a few new options. Using "-c KEEPOUTPUTFILE=y" one can specifically keep that file instead of using -kkk. The number of -kk has also changed as the default has changed to skip the saved.tar generation.
Additionally it is possible to provide a path to some --docker=/other/binary but tests with podman have shown that it is incompatible (although the bug reports show that it may be fixed in the next version of podman).
The provided setup.cfg file allows to package a bdist_wheel universal distribution.