At the moment `PytestTestEngine` runs command `py.test --junit-xml=<path to tmp file>`. Beside changing the class itself, I found no way how to configure this. We'd like to be able to set that `arc unit` runs our unit and functional tests (e.g with heavy I/O) and `py.test` from command line runs only unit tests. So during development we do quick manual check from command line and later we run full tests using `arc diff`.
The solution using `py.test` and `tox.ini` is somehow hacky and it would be nice to have a way how to set how the `py.test` is run just like in the case of linting. Or is this already present in arcanist and I missed something?