Checks that the conda environment file is valid.


This test is ignored if there is not an environment.yml file present in the pipeline root directory.

DSL1 nf-core pipelines use a single Conda environment to manage all software dependencies for a workflow. This can be used directly with -profile conda and is also used in the Dockerfile to build a docker image.

This test checks the conda environment.yml file to ensure that it follows nf-core guidelines. Each dependency is checked using the Anaconda API service. Dependency sublists are ignored with the exception of - pip: these packages are also checked for pinned version numbers and checked using the PyPI JSON API.

Specifically, this lint test makes sure that:

  • The environment name must match the pipeline name and version
    • The pipeline name is defined in the config variable
    • Replace the slash with a hyphen as environment names shouldn’t contain that character
    • Example: For nf-core/test version 1.4, the conda environment name should be nf-core-test-1.4
  • All package dependencies have a specific version number pinned

    Remember that Conda package versions should be pinned with one equals sign (toolname=1.1), but pip uses two (toolname==1.2)

  • That package versions can be found and are the latest available
    • Test will go through all conda channels listed in the file, or check PyPI if pip
    • Conda dependencies with pinned channels (eg. conda-forge::openjdk) are ok too
    • In addition to the package name, the pinned version is checked
    • If a newer version is available, a warning will be reported