Conda package for nextstrain-base

This is the source for creating the nextstrain-base Conda package.

This meta-package depends on all the other packages needed for a base Nextstrain runtime installed as a Conda environment. As the nextstrain/base image is to Nextstrain CLI's Docker runtime, this nextstrain-base package is to Nextstrain CLI's Conda runtime. The package's dependencies which completely lock its full transitive dependency tree. This means that if version X of nextstrain-base worked some way in the past, it'll work the same way in the future.

Note that this is not a general purpose package for installing Nextstrain. It's intended for use by Nextstrain CLI's managed Conda runtime and may be unsuitable for use in a user-managed Conda environment.

How it works

The meta-package source recipe is in src/meta.yaml. This is a conda-build recipe spec. It defines our runtime's direct dependencies, typically without version restrictions (pins) or with only loose pinning as necessary. The recipe declares pin_depends: strict in order to fully lock its dependency tree at package build time.

As the fully locked dependency trees are platform-specific, CI produces packages for both Linux and macOS (i.e. for Conda's linux-64 and osx-64 subdirs).

Developing

You can build this package locally during development, but it's important for production releases to happen via CI so packages are built for both Linux and macOS.

First, setup a Conda environment for development in .dev-env/ so that conda-build is available.

./devel/setup

You only need to do this once, or whenever you want to refresh your development environment. Either Micromamba, Mamba, or Conda must be available for setup to succeed. You do not need to create a new environment yourself, the script automatically sets everything up without interfering with your existing environments.

Building

To build this package locally, run:

./devel/build

The final built package will be written to build/<arch>/nextstrain-base-*.conda, where <arch> is a Conda subdir, i.e. linux-64, osx-64 or osx-arm64.

CI builds store the entire build/ directory as an artifact attached to each CI run. You can download the artifacts to inspect the built packages or install them.

Installing

To install the built package into a new environment, run:

mamba create                              \
  --prefix /path/to/new/env               \
  --strict-channel-priority               \
  --override-channels                     \
  --channel conda-forge                   \
  --channel bioconda                      \
  --channel ./build/                      \
  nextstrain-base

Uploading

To upload the built package to anaconda.org, run:

./devel/upload

You'll need an appropriate Anaconda API token set in the ANACONDA_TOKEN environment variable. The token must have at least the api:read, api:write, and conda scopes attached to it. CI uses a token issued for the Nextstrain Anaconda organization.

You can adjust the label applied to the uploaded package by setting the LABEL environment variable. By default the Git ref is used to determine the label:

• Uploads from our main branch are given the main label. These packages will be found by default for anyone using our Anaconda channel (e.g. --channel nextstrain).

• Uploads from other branches, tags, and PRs will get branch-<name>, tag-<name>, and pull-<number> labels. These packages can be used by asking for them explicitly (e.g. --channel nextstrain/label/pull-123).

If no label can be worked out, then dev is used as a final fallback.

CI uploads the built package if it passes the test phase. You can use the above labels to install CI-uploaded packages locally without downloading the CI artifacts.

Repository layout

src/ contains the package recipe source. Any files in this directory will be automatically included in the built package. (meta.yaml doesn't live in the top-level of the repo, and thus src/ exists, to avoid including the whole repo in each built package.)

build/ contains build outputs not tracked in version control.

devel/ contains programs for development of this package.

.condarc is used to specify configuration (e.g. channels) for conda build.

History

• Initial suggestion of the meta-package on the Nextstrain CLI PR introducing the Conda runtime.

• Further discussion about the meta-package on Slack, motivated by the Conda runtime breaking between one day and the next due to upstream changes.