as reported [here](https://github.com/pytest-dev/pytest/issues/7053#issuecomment-638551342) and confirmed by my tests, branch `fixture-stack` runs a parametrized fixture a suboptimal amount of times. running [this example](https://repl.it/@oakkitten/RightSomberDatabases), output using current upstream master (5.4.1.dev422+gcf640a9b6, also 3.10.1 and some versions in between): ``` test_cats_dogs.py dog charlie cat tom .sssdog buddy ss.scat simba sss.dog charlie s.ss ``` output from `fixtue-stack`: ``` test_cats_dogs.py dog charlie cat tom .sssdog buddy cat tom ss.scat simba sss.dog charlie cat simba s.ss ```