How do I force `setup.py test` to install dependencies into my `virtualenv`?

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.

If you are using setuptools, you can specify test dependencies using the tests_require keyword argument for the setup method.

from setuptools import setupsetup(    name='your-package-name',    version='1.0.0',    author='me',    author_email='me@mybasement.com',    install_requires=['Pygments>=1.4'],    tests_require=['nose'],    packages=[        'your_package_name',    ],)

When you run python setup.py test, this will check for nose and install it to the currently active virtualenv using pip if not already available.

Note that this argument will be ignored if you are using distribute.core.setup (nor will a test command be available).