title: Coverage not finding tests
body: <p>Coverage doesn't seem to be picking up the &quot;coverage&quot; of the tests in the directory <code>tests</code>. The source files are in a directory <code>src</code>. (File names have been changed to protect the innocent.)</p>
  <p>Here is the tox.ini:</p>
  <pre><code>[tox]
  envlist = py3
  
  
  [testenv]
  extras = test
  commands =
      pip list --format=columns
      coverage run --rcfile=.coveragerc -m pytest --full-trace -l --strict -v
      coverage combine --append
      coverage report -im
      coverage html -i
  exclude =
      .tox,
      .git,
      __pycache__,
      'src/reports',
      'src/target_files',
      test,
      venv
  
  
  [flake8]
  exclude =
      .tox,
      .git,
      __pycache__,
      'src/reports',
      'src/target_files',
      test,
      venv
  max-line-length = 111
  </code></pre>
  <p>Here is the coveragerc:</p>
  <pre><code>[run]
  branch=True
  context=src
  omit = test
  source=
      src
  timid=True
  parallel=True
  [report]
  omit=
      .tox/*
  </code></pre>
  <p>Here is the setup.py:</p>
  <pre><code>from setuptools import setup
  from setuptools import find_packages
  
  _INSTALL_REQUIRES = [
      &quot;pytest&quot;
  ]
  _EXTRAS_REQUIRE = {
    &quot;test&quot;: [
      &quot;flake8&quot;,
      &quot;coverage&quot;,
      &quot;mock&quot;,
      &quot;setuptools&quot;
    ]
  }
  
  setup(
      author='...',
      author_email='...',
      description='',
      extras_require=_EXTRAS_REQUIRE,
      include_package_data=True,
      install_requires=_INSTALL_REQUIRES,
      license='',
      name='...',
      package_dir={'': 'src'},
      packages=find_packages(where=&quot;src&quot;),
      url='',
      version='1'
  )
  </code></pre>
  <p>This outputs:</p>
  <pre><code>Coverage.py warning: No data was collected. (no-data-collected)
  py3 run-test: commands[2] | coverage combine --append
  py3 run-test: commands[3] | coverage report -im
  Name                               Stmts   Miss Branch BrPart  Cover   Missing
  ------------------------------------------------------------------------------
  src/__init__.py                        0      0      0      0   100%
  src/[file].py                          7      7      0      0     0%   1- 13
  src/[file].py                         13     13      0      0     0%   1-18
  src/lib/__init__.py                    0      0      0      0   100%
  src/lib/[file].py                     83     83     26      0     0%   1-161
  src/lib/[file].py                     49     49     16      0     0%   1-67
  src/lib/[file].py                     92     92     22      0     0%   1-117
  src/lib/[file].py                     47     47     20      0     0%   1-71
  src/lib/[file].py                     34     34      8      0     0%   1-42
  ------------------------------------------------------------------------------
  TOTAL                                325    325     92      0     0%
  </code></pre>
  <p>There are tests for each of the files in this list. What can I do to get coverage to notice them?</p>