Migrate development workflow to Pixi

.gitattributes

@@ -2,3 +2,5 @@
 doc/whats-new.rst merge=union
 # allow installing from git archives
 .git_archival.txt  export-subst
+# SCM syntax highlighting & preventing 3-way merges
+pixi.lock merge=binary linguist-language=YAML linguist-generated=true

.github/workflows/benchmarks.yml

@@ -9,7 +9,10 @@ env:
   PR_HEAD_LABEL: ${{ github.event.pull_request.head.label }}
 
 jobs:
+  cache-pixi-lock:
+    uses: ./.github/workflows/cache-pixi-lock.yml
   benchmark:
+    needs: cache-pixi-lock
     if: ${{ contains( github.event.pull_request.labels.*.name, 'run-benchmark') && github.event_name == 'pull_request' || contains( github.event.pull_request.labels.*.name, 'topic-performance') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch' }}
     name: Linux
     runs-on: ubuntu-latest
@@ -24,6 +27,18 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Restore cached pixi lockfile
+        uses: actions/cache/restore@v4
+        id: restore-pixi-lock
+        with:
+          path: |
+            pixi.lock
+          key: ${{ needs.cache-pixi-lock.outputs.cache-id }}
+      - uses: prefix-dev/[email protected]
+        with:
+          cache: true
+          cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
+
       - name: Set up conda environment
         uses: mamba-org/setup-micromamba@v2
         with:

.github/workflows/cache-pixi-lock.yml

@@ -0,0 +1,52 @@
+name: Generate and cache Pixi lockfile
+
+on:
+  workflow_call:
+    inputs:
+      pixi-version:
+        type: string
+    outputs:
+      cache-id:
+        description: "The lock file contents"
+        value: ${{ jobs.cache-pixi-lock.outputs.cache-id }}
+
+jobs:
+  cache-pixi-lock:
+    name: Generate output
+    runs-on: ubuntu-latest
+    outputs:
+      cache-id: ${{ steps.restore.outputs.cache-primary-key }}
+    steps:
+      - uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+          submodules: recursive
+      - name: Get current date
+        id: date
+        run: echo "date=$(date +'%Y-%m-%d')" >> "$GITHUB_OUTPUT"
+      - uses: actions/cache/restore@v4
+        id: restore
+        with:
+          path: |
+            pixi.lock
+          key: ${{ steps.date.outputs.date }}_${{ inputs.pixi-version }}_${{hashFiles('pixi.toml')}}
+      - uses: prefix-dev/[email protected]
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        with:
+          pixi-version: ${{ inputs.pixi-version }}
+          run-install: false
+      - name: Run pixi lock
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        run: pixi lock
+      - uses: actions/cache/save@v4
+        if: ${{ !steps.restore.outputs.cache-hit }}
+        id: cache
+        with:
+          path: |
+            pixi.lock
+          key: ${{ steps.restore.outputs.cache-primary-key }}
+      - name: Upload pixi.lock
+        uses: actions/upload-artifact@v4
+        with:
+          name: pixi-lock
+          path: pixi.lock

.github/workflows/ci-additional.yaml

@@ -319,10 +319,10 @@ jobs:
         uses: xarray-contrib/minimum-dependency-versions@e2ac8ff0a76e8603d8536ef5d64743a375961ce9 # v0.1.1
         with:
           policy: ci/policy.yaml
-          environment-paths: ci/requirements/min-all-deps.yml
+          environment-paths: ci/requirement-linting/min-all-deps.yml
 
       - name: Bare minimum versions policy
         uses: xarray-contrib/minimum-dependency-versions@e2ac8ff0a76e8603d8536ef5d64743a375961ce9 # v0.1.1
         with:
           policy: ci/policy.yaml
-          environment-paths: ci/requirements/bare-minimum.yml
+          environment-paths: ci/requirement-linting/bare-minimum.yml

.github/workflows/ci.yaml

@@ -32,10 +32,15 @@ jobs:
         id: detect-trigger
         with:
           keyword: "[skip-ci]"
+
+  cache-pixi-lock:
+    uses: ./.github/workflows/cache-pixi-lock.yml
+    with:
+      pixi-version: "v0.58.0" # keep in sync with jobs
   test:
-    name: ${{ matrix.os }} py${{ matrix.python-version }} ${{ matrix.env }}
+    name: "${{ matrix.os }} | pixi shell -e ${{ matrix.pixi-env }}"
     runs-on: ${{ matrix.os }}
-    needs: detect-ci-trigger
+    needs: [detect-ci-trigger, cache-pixi-lock]
     if: needs.detect-ci-trigger.outputs.triggered == 'false'
     defaults:
       run:
@@ -45,110 +50,87 @@ jobs:
       matrix:
         os: ["ubuntu-latest", "macos-latest", "windows-latest"]
         # Bookend python versions
-        python-version: ["3.11", "3.13"]
-        env: [""]
+        pixi-env: ["test-all-deps-py311", "test-all-deps-py313"]
+        pytest-adopts: [""]
         include:
           # Minimum python version:
-          - env: "bare-minimum"
-            python-version: "3.11"
-            os: ubuntu-latest
-          - env: "bare-min-and-scipy"
-            python-version: "3.11"
+          - pixi-env: "test-bare-minimum"
             os: ubuntu-latest
-          - env: "min-all-deps"
-            python-version: "3.11"
+          - pixi-env: "test-bare-min-and-scipy"
             os: ubuntu-latest
+          # - pixi-env: "min-all-deps" # TODO: include later by duplicating old workflow and using conda. Not using Pixi for now.
+          #   python-version: "3.11"
+          #   os: ubuntu-latest
           # Latest python version:
-          - env: "all-but-numba"
-            python-version: "3.13"
+          - pixi-env: "test-all-but-numba"
             os: ubuntu-latest
-          - env: "all-but-dask"
-            python-version: "3.12"
+          - pixi-env: "test-all-but-dask"
             os: ubuntu-latest
-          - env: "flaky"
-            python-version: "3.13"
+          - pixi-env: "test-all-deps-py313"
+            pytest-adopts: "flaky"
             os: ubuntu-latest
           # The mypy tests must be executed using only 1 process in order to guarantee
           # predictable mypy output messages for comparison to expectations.
-          - env: "mypy"
-            python-version: "3.11"
+          - pixi-env: "test-all-mypy-py311"
+            pytest-adopts: "mypy"
             numprocesses: 1
             os: ubuntu-latest
-          - env: "mypy"
-            python-version: "3.13"
+          - pixi-env: "test-all-mypy-py313"
             numprocesses: 1
             os: ubuntu-latest
     steps:
       - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
+      - name: Restore cached pixi lockfile
+        uses: actions/cache/restore@v4
+        id: restore-pixi-lock
+        with:
+          enableCrossOsArchive: true
+          path: |
+            pixi.lock
+          key: ${{ needs.cache-pixi-lock.outputs.cache-id }}
+      - uses: prefix-dev/[email protected]
+        with:
+          pixi-version: "v0.58.0" # keep in sync with cache-pixi-lock
+          cache: true
+          environments: ${{ matrix.pixi-env }}
+          cache-write: ${{ github.event_name == 'push' && github.ref_name == 'main' }}
+
       - name: Set environment variables
         run: |
           echo "TODAY=$(date +'%Y-%m-%d')" >> $GITHUB_ENV
 
-          if [[ ${{ matrix.os }} == windows* ]] ;
-          then
-            if [[ ${{ matrix.python-version }} != "3.14" ]]; then
-              echo "CONDA_ENV_FILE=ci/requirements/environment-windows.yml" >> $GITHUB_ENV
-            else
-              echo "CONDA_ENV_FILE=ci/requirements/environment-windows-3.14.yml" >> $GITHUB_ENV
-            fi
-          elif [[ "${{ matrix.env }}" != "" ]] ;
+          if [[ "${{ matrix.pytest-adopts }}" != "" ]] ;
           then
-            if [[ "${{ matrix.env }}" == "flaky" ]] ;
+            if [[ "${{ matrix.pytest-adopts }}" == "flaky" ]] ;
             then
-              echo "CONDA_ENV_FILE=ci/requirements/environment.yml" >> $GITHUB_ENV
               echo "PYTEST_ADDOPTS=-m 'flaky or network' --run-flaky --run-network-tests -W default" >> $GITHUB_ENV
-            elif [[ "${{ matrix.env }}" == "mypy" ]] ;
+            elif [[ "${{ matrix.pytest-adopts }}" == "mypy" ]] ;
             then
-              echo "CONDA_ENV_FILE=ci/requirements/environment.yml" >> $GITHUB_ENV
               echo "PYTEST_ADDOPTS=-n 1 -m 'mypy' --run-mypy -W default" >> $GITHUB_ENV
-            else
-              echo "CONDA_ENV_FILE=ci/requirements/${{ matrix.env }}.yml" >> $GITHUB_ENV
             fi
-            if [[ "${{ matrix.env }}" == "min-all-deps" ]] ;
+            if [[ "${{ matrix.pixi-env }}" == "min-all-deps" ]] ;
             then
               # Don't raise on warnings
               echo "PYTEST_ADDOPTS=-W default" >> $GITHUB_ENV
             fi
-          else
-            if [[ ${{ matrix.python-version }} != "3.14" ]]; then
-              echo "CONDA_ENV_FILE=ci/requirements/environment.yml" >> $GITHUB_ENV
-            else
-              echo "CONDA_ENV_FILE=ci/requirements/environment-3.14.yml" >> $GITHUB_ENV
-            fi
           fi
 
-          echo "PYTHON_VERSION=${{ matrix.python-version }}" >> $GITHUB_ENV
-
-      - name: Setup micromamba
-        uses: mamba-org/setup-micromamba@v2
-        with:
-          environment-file: ${{ env.CONDA_ENV_FILE }}
-          environment-name: xarray-tests
-          cache-environment: true
-          cache-environment-key: "${{runner.os}}-${{runner.arch}}-py${{matrix.python-version}}-${{env.TODAY}}-${{hashFiles(env.CONDA_ENV_FILE)}}"
-          create-args: >-
-            python=${{matrix.python-version}}
-
       # We only want to install this on one run, because otherwise we'll have
       # duplicate annotations.
       - name: Install error reporter
-        if: ${{ matrix.os }} == 'ubuntu-latest' and ${{ matrix.python-version }} == '3.12'
-        run: |
-          python -m pip install pytest-github-actions-annotate-failures
-
-      - name: Install xarray
+        if: ${{ matrix.os }} == 'ubuntu-latest' and ${{ matrix.pixi-env}} == 'test-all-deps-py313'
         run: |
-          python -m pip install --no-deps -e .
+          pixi add --pypi pytest-github-actions-annotate-failures
 
       - name: Version info
         run: |
-          python xarray/util/print_versions.py
+          pixi run -e ${{ matrix.pixi-env }} python xarray/util/print_versions.py
 
       - name: Import xarray
         run: |
-          python -c "import xarray"
+          pixi run -e ${{ matrix.pixi-env }} python -c "import xarray"
 
       - name: Restore cached hypothesis directory
         uses: actions/cache@v4
@@ -159,7 +141,8 @@ jobs:
           save-always: true
 
       - name: Run tests
-        run: python -m pytest -n ${{ matrix.numprocesses || 4 }}
+        run:
+          pixi run -e ${{ matrix.pixi-env }} python -m pytest -n ${{ matrix.numprocesses || 4 }}
           --timeout 180
           --cov=xarray
           --cov-report=xml
@@ -169,7 +152,7 @@ jobs:
         if: always()
         uses: actions/upload-artifact@v5
         with:
-          name: Test results for ${{ runner.os }}-${{ matrix.python-version }} ${{ matrix.env }}
+          name: Test results for OS ${{ runner.os }} pixi-env -${{ matrix.pixi-env }}
           path: pytest.xml
 
       - name: Upload code coverage to Codecov
@@ -179,7 +162,7 @@ jobs:
         with:
           file: ./coverage.xml
           flags: unittests
-          env_vars: RUNNER_OS,PYTHON_VERSION
+          env_vars: RUNNER_OS
           name: codecov-umbrella
           fail_ci_if_error: false
 

.gitignore

@@ -91,3 +91,7 @@ doc/videos-gallery.txt
 uv.lock
 mypy_report/
 xarray-docs/
+
+# pixi environments
+.pixi
+pixi.lock

.readthedocs.yaml

@@ -7,16 +7,23 @@ sphinx:
 build:
   os: ubuntu-lts-latest
   tools:
-    python: mambaforge-latest
+    # just so RTD stops complaining
+    python: "latest"
   jobs:
+    create_environment:
+      - asdf plugin add pixi
+      - asdf install pixi latest
+      - asdf global pixi latest
     post_checkout:
       - (git --no-pager log --pretty="tformat:%s" -1 | grep -vqF "[skip-rtd]") || exit 183
       - git fetch --unshallow || true
     pre_install:
-      - git update-index --assume-unchanged doc/conf.py ci/requirements/doc.yml
-
-conda:
-  environment: ci/requirements/doc.yml
+      - git update-index --assume-unchanged doc/conf.py
+    install:
+      - pixi install -e doc
+    build:
+      html:
+        - BUILDDIR=$READTHEDOCS_OUTPUT pixi run -e doc make html
 
 formats:
   - htmlzip

README.md

@@ -1,5 +1,7 @@
 # xarray: N-D labeled arrays and datasets
 
+[![Xarray](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/pydata/xarray/refs/heads/main/doc/badge.json)](https://xarray.dev)
+[![Powered by Pixi](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/prefix-dev/pixi/main/assets/badge/v0.json)](https://pixi.sh)
 [![CI](https://github.com/pydata/xarray/actions/workflows/ci.yaml/badge.svg?branch=main)](https://github.com/pydata/xarray/actions/workflows/ci.yaml?query=branch%3Amain)
 [![Code coverage](https://codecov.io/gh/pydata/xarray/branch/main/graph/badge.svg?flag=unittests)](https://codecov.io/gh/pydata/xarray)
 [![Docs](https://readthedocs.org/projects/xray/badge/?version=latest)](https://docs.xarray.dev/)
@@ -12,7 +14,6 @@
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.598201.svg)](https://doi.org/10.5281/zenodo.598201)
 [![Examples on binder](https://img.shields.io/badge/launch-binder-579ACA.svg?logo=data:image/png;base64,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)](https://mybinder.org/v2/gh/pydata/xarray/main?urlpath=lab/tree/doc/examples/weather-data.ipynb)
 [![Twitter](https://img.shields.io/twitter/follow/xarray_dev?style=social)](https://x.com/xarray_dev)
-[![image](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/pydata/xarray/refs/heads/main/doc/badge.json)](https://xarray.dev)
 
 **xarray** (pronounced "ex-array", formerly known as **xray**) is an open source project and Python
 package that makes working with labelled multi-dimensional arrays

ci/requirement-linting/bare-minimum.yml

@@ -0,0 +1,18 @@
+name: xarray-tests #! keep this file in sync with pixi.toml
+channels:
+  - conda-forge
+  - nodefaults
+dependencies:
+  - python=3.11
+  - coveralls
+  - pip
+  - pytest
+  - pytest-asyncio
+  - pytest-cov
+  - pytest-env
+  - pytest-mypy-plugins
+  - pytest-timeout
+  - pytest-xdist
+  - numpy=1.26
+  - packaging=24.1
+  - pandas=2.2

ci/requirements/min-all-deps.yml → ci/requirement-linting/min-all-deps.yml

@@ -1,4 +1,4 @@
-name: xarray-tests
+name: xarray-tests #! keep this file in sync with pixi.toml
 channels:
   - conda-forge
   - nodefaults