Nilearn maintenance process

Project Organization


Nilearn uses issues for tracking bugs, requesting potential features, and holding project discussions.

Core developers can assign labels on issues, such as:

  • Discussion These issues discuss ongoing discussions on the project where community feedback is requested.

  • Enhancement These issues discuss potential enhancements or additions to the project.

  • Bug These issues detail known bugs in the Nilearn code base.

Pull Requests

We welcome pull requests from all community members, if they follow the Contribution Guidelines inspired from scikit learn conventions. (More details on their process are available here)

How to make a release?

This section describes how to make a new release of Nilearn. It is targeted to the specific case of Nilearn although it contains generic steps for packaging and distributing projects. More detailed information can be found on

We assume that we are in a clean state where all the Pull Requests (PR) that we wish to include in the new release have been merged. For example, make sure all deprecations that are supposed to be removed with this new version have been addressed. Furthermore, if this new release comes with dependency version bumps (Python, Numpy…), make sure to implement and test these changes beforehand. Ideally, these would have been done before such as to update the code base if necessary. Finally, make sure the documentation can be built correctly.

Prepare the release

Switch to a new branch locally:

git checkout -b REL-x.y.z

First we need to prepare the release by updating the file nilearn/doc/whats_new.rst to make sure all the new features, enhancements, and bug fixes are included in their respective sections. We also need to write a “Highlights” section promoting the most important additions that come with this new release, and add the version tag just above the corresponding title:

.. _vx.y.z:

**Released MONTH YEAR**


- Nilearn now includes functionality A
- ...

Next, we need to bump the version number of Nilearn by updating the file nilearn/ with the new version number, that is edit the line:

__version__ =

to be:

__version__ = x.y.z

We also need to update the website news section by editing the file nilearn/doc/themes/nilearn/layout.html. The news section typically contains links to the last 3 releases that should look like:

<h4> News </h4>
        <li><p><strong>November 2020</strong>:
            <a href="whats_new.html#v0-7-0">Nilearn 0.7.0 released</a>
        <li><p><strong>February 2020</strong>:
            <a href="whats_new.html#v0-6-2">Nilearn 0.6.2 released</a>
        <li><p><strong>January 2020</strong>:
            <a href="whats_new.html#v0-6-1">Nilearn 0.6.1 released</a>

Here, we should remove the last entry and add the new release on top of the list.

In addition, we can have a look at to check that all additional files that we want to be included or excluded from the release are indicated. Normally we shouldn’t have to touch this file.

Add these changes and submit a PR:

git add doc/whats_new.rst nilearn/
git commit -m "REL x.y.z"
git push origin REL-x.y.z

Once the PR has been reviewed and merged, pull from master and tag the merge commit:

git checkout master
git pull upstream master
git tag x.y.z
git push upstream --tags

Build the distributions and upload them to Pypi

First of all we should make sure we don’t include files that shouldn’t be present:

git checkout x.y.z

If the workspace contains a dist folder, make sure to clean it:

rm -r dist

In order to build the binary wheel files, we need to install wheel:

pip install wheel

And, in order to upload to Pypi, we will use twine that you can also install with pip:

pip install twine

Build the source and binary distributions:

python sdist bdist_wheel

This should add two files to the dist subfolder:

  • one for the source distribution that should look like PACKAGENAME-VERSION.tar.gz

  • one for the built distribution that should look like PACKAGENAME-PACKAGEVERSION-PYTHONVERSION-PYTHONCVERSION-PLATFORM.whl

Optionally, we can run some basic checks with twine:

twine check dist/*

We are now ready to upload to Pypi. Note that you will need to have an account on Pypi, and be added to the maintainers of Nilearn. If you satisfy these conditions, you should be able to run:

twine upload dist/*

Once the upload is completed, make sure everything looks good on Pypi. Otherwise you will probably have to fix the issue and start over a new release with the patch number incremented.

At this point, we need to upload the binaries to GitHub and link them to the tag. To do so, go to the Nilearn GitHub page under the “Releases” tab, and edit the x.y.z tag by providing a description, and upload the distributions we just created (you can just drag and drop the files).

Build and deploy the documentation

We now need to update the documentation:

cd doc
make install

This will build the documentation (beware, this is time consuming…) and push it to the GitHub pages repo.


At this point, the release has been made. We can now update the file nilearn/ and update the version number by increasing the patch number and appending .dev:

__version__ = x.y.(z+1).dev

We can also update the file doc/whats_new.rst by adding a title and the usual New, Enhancements, and Bug Fixes sections for the version currently under development:




.. _vx.y.z: