This section is to help contributors get up to speed on various topics related to building and testing conda packages.
What’s the difference between Anaconda, conda, and Miniconda?¶
The Anaconda Python distribution started out as a bundle of scientific Python packages that were otherwise difficult to install. It was created by ContinuumIO and remains the easiest way to install the full scientific Python stack.
Many packaging problems had to be solved in order to provide a cross-platform bundle, and one of the tools that came out of that work was the conda package manager. So conda is part of Anaconda. But conda ended up being very useful on its own and for things other than Python, so ContinuumIO spun it out into its own separate open-source package.
However, conda is not just for Python, it is not “pip-installable” and rather needs to be installed in a language-agnostic manner. The conda installer is called Miniconda, to differentiate it from the full-size Anaconda.
So: conda is a package manager, Miniconda is the conda installer, and Anaconda is a scientific Python distribution that also includes conda.
Recipe vs package¶
A recipe is a directory containing small set of files that defines name,
version, dependencies, and URL for source code. A recipe typically contains
meta.yaml file that defines these settings and a
build.sh script that
builds the software. A recipe is converted into a package by running
conda-build on the recipe. A package is a bgzipped tar file (
contains the built software. Packages are uploaded to anaconda.org so that
users can install them with
Conda package specification has details on exactly
what a package contains and how it is installed into an
Continuous integration (Circle CI)¶
We use the Circle CI continuous integration service. Continuous integration
tests each small incremental change to code to ensure that everything is
up-to-date and correct. Circle CI graciously provides this service for free to
open-source projects. It is connected to GitHub such that each time a pull
request or merge occurs, a new Circle CI build is created. For bioconda,
a “build” means identifying any recipes that need to built, running
conda-build on them, and testing to make sure they work.
How is Circle CI set up and configured?¶
.circleci/config.ymlis read by the Circle CI worker.
The worker runs
.circleci/setup.sh. This installs conda, adds channels, and installs bioconda-utils
The worker runs tests defined in
A local version of the Circle CI tests can be executed via the Circle CI client. Note that this version lacks some additional tests that are executed in the online version. Thus, it can be that a local test passes while the online test fails. Nevertheless, the local test should capture most problems, such that it is highly encouraged to first run a local test in order to save quota on Circle CI.
How are dependencies pinned to particular versions?¶
In some cases a recipe may need to pin the version of a dependency.
A global set of default versions to pin against is shared with conda-forge and
can be found here.
For new dependencies that are contained in conda-forge and not yet in this list,
please update the list via a pull request.
Local pinnings can be achieved by adding a file
To find out against which version you can pin a package, e.g. x.y.* or x.* please use ABI-Laboratory.
What’s the lifecycle of a bioconda package?¶
Submit a pull request with a new recipe or an updated recipe
Circle CI automatically builds and tests the changed recipe[s] using conda-build. Test results are shown on the PR.
If tests fail, push changes to PR until they pass.
Once tests pass, merge into master branch
Circle CI tests again, but this time after testing the built packages are uploaded to the bioconda channel on anaconda.org.
Users can now install the package just like any other conda package with
Once uploaded to anaconda.org, it is our intention to never delete any old
packages. Even if a recipe in the bioconda repo is updated to a new version,
the old version will remain on anaconda.org. ContinuumIO has graciously agreed
to sponsor the storage required by the bioconda channel.
Nevertheless, it can sometimes happen that we have to mark packages as broken
in order to avoid that they are accidentally pulled by the conda solver.
In such a case it is only possible to install them by specifically considering
broken label, i.e.,
conda install -c conda-forge -c bioconda -c defaults -c bioconda/label/broken my-package=<broken-version>
CircleCI macOS plans¶
In the past we had recommended enabling CircleCI for your fork to help conserve the bioconda team’s build time quota. However this did not work very well: macOS builds on CircleCI require an extra macOS plan, which is not free to users. The result was that contributors’ pull requests would fail tests simply due to not having a paid macOS plan. Luckily, CircleCI has generously provided macOS builds to the bioconda team.
To ensure that CircleCI uses the bioconda team account, please disable CircleCI on your fork (look for the big red “Stop Building” button at https://circleci.com/dashboard under the settings for your fork).
Follow the instructions at Using the “Bootstrap” Method to create a separate Miniconda
installation using the
bootstrap.py script in the
Then, in the activated environment, install the bioconda-utils test
requirements, from the top-level directory of the
While the bootstrap script installs bioconda-utils dependencies, if there are
any changes in
requirements.txt you will want to install them as well.
The bootstrap script already installed bioconda-utils, but we want to install it in develop mode so we can make local changes and they will be immediately picked up. So we need to uninstall and then reinstall bioconda-utils.
Finally, run the tests using
# activate env source ~/.config/bioconda/activate # install dependencies conda install --file test-requirements.txt --file bioconda_utils/bioconda_utils-requirements.txt # uninstall and then reinstall pip uninstall bioconda_utils python setup.py develop # run tests pytest test -vv
Where can I find more info on
meta.yaml file is conda’s metadata definition file for recipes.
If you are developing a new recipe or are trying to update or improve an existing one, it can be helpful to know
which elements and values can appear in
Conda has this information available here. Please check that you are looking at the correct version of the documentation for the current conda version used by bioconda.