By design, you can’t make the tests_requires or the setup_requires entries go into the virtual environment. The idea is to separate what is required for performing tests/setup and what is required to actually use the package being installed. For example, I may require that the “coverage” module be needed for running tests on my package, but it isn’t used by any of my code in the package. Therefore, if I didn’t have “coverage” in my environment when I go and run tests, I wouldn’t want “coverage” to get installed into the environment if my package didn’t need it.