Development Setup Notes

The following are some useful notes for setting up an environment to work on coala.


We highly recommend installing coala in a virtualenv for development. This will allow you to have a contained environment in which to modify coala, separate from any other installation of coala that you may not want to break. Here we will be showing how to have a virtualenv using venv and virtualenv. We recommend using venv as it is part of the standard library and requires no extra installation. However, you can use whichever you find suitable to yourself.

Using venv

  • Make sure to have Python 3 installed in your local machine.

  • Setting up virtualenv with venv :
    $ cd working_dir # move into the dir where you want to create coala-venv
    $ python3 -m venv coala-venv
    # This creates a isolated python environment called coala-venv
    # in your current directory.
    # To activate the environment type:
    $ source coala-venv/bin/activate
    # To exit the environment simply type:
    (coala-venv)$ deactivate
  • Now you can activate the environment and start the next part.

Using virtualenv

  • Install virtualenv using pip :
    $ pip install virtualenv
  • Create the virtualenv :
    $ cd working_dir # move into the dir where you want to create coala-venv
    $ virtualenv coala-venv
  • Run coala-venv :
    $ source coala-venv/bin/activate
    (coala-venv)$ deactivate # to exit the environment
  • After this, you can start installing from git.


If you are interested in contributing to coala, we recommend that you read our newcomers’ guide to familiarize yourself with our workflow, and perhaps with GitHub itself.

You will most likely need to work only in the coala or coala-bears repository. The former is the core of coala, and the latter contains the set of standard bears. You can fork and clone the repositories from:

Installing from Git

We recommend first installing the latest development snapshot of coala’s master branch from and all of its dependencies with pip using

(coala-venv)$ git clone
(coala-venv)$ cd coala
(coala-venv)$ pip3 install -e .
(coala-venv)$ cd -
(coala-venv)$ git clone
(coala-venv)$ cd coala-bears
(coala-venv)$ pip3 install -e .

Then you can install a repository-backed version of the repository you would like to modify using

(coala-venv)$ pip3 install -e <path/to/clone>

You will then be able to edit the repository and have the changes take effect in your virtualenv immediately. You will also be able to use pip to manage your installation of the package should you need to install from a different source in the future.

Building Documentation

You should run this command before trying to build the documentation:

(coala-venv)$ pip3 install -r docs-requirements.txt

Once you have done so, you can build the documentation by entering the docs directory and running make. The documentation on the coala website is in the coala (not coala-bears) repository.