Add instructions for running pip from source to docs
@@ -17,6 +17,16 @@ and ensuring reproducible environments for linting and building documentation.
For developing pip, you need to install ``tox`` on your system. Often, you can
just do ``python -m pip install tox`` to install and use it.
+Running pip From Source Tree
+----------------------------
+
+To run the pip executable from your source tree during development, run the
+executable from a ``tox`` environment, after having run the tests:
+
+.. code-block:: console
+
+ $ .tox/py36/bin/pip --version
+
Running Tests
-------------
