Implement release workflow for mess and mess-static

.github/workflows/build.yml

@@ -2,10 +2,28 @@ name: Build and test
 
 on:
   push:
+    branches: ["**"]  # not tags: a release tag runs this workflow through release.yml
   pull_request:
   workflow_dispatch:
+  workflow_call:
 
 jobs:
+  workflows:
+    name: lint the workflows
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: prefix-dev/setup-pixi@v0.11.3
+        with:
+          pixi-version: v0.84.1
+          environments: release
+          cache: true
+          cache-write: ${{ github.event_name == 'push' && github.ref_name == 'master' }}
+
+      - name: Lint the GitHub Actions workflows
+        run: pixi run workflows
+
   build-test:
     name: ${{ matrix.environment }}
     runs-on: ubuntu-latest
@@ -41,12 +59,3 @@ jobs:
         with:
           name: mess-static-linux-64
           path: .pixi/envs/static/bin/mess*
-
-      - name: Upload mess-static to the Auto-Mech channel
-        if: matrix.environment == 'static' && github.event_name == 'push' && github.ref_name == 'master' && github.repository_owner == 'Auto-Mech'
-        run: |
-          pixi publish --path static --target-dir dist
-          # As before: an upload of an existing version fails, which is not an error here
-          pixi exec rattler-build upload anaconda -o Auto-Mech dist/*.conda || true
-        env:
-          ANACONDA_API_KEY: ${{ secrets.ANACONDA_API_KEY }}

.github/workflows/release.yml

@@ -0,0 +1,98 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - "v*.*.*"
+
+permissions:
+  contents: read
+
+jobs:
+  # Releases are made from master only: stop if the tag is on another branch
+  check:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0  # all branches, to compare the tag with master
+
+      - name: Check that the tagged commit is on master
+        run: git merge-base --is-ancestor "$GITHUB_SHA" origin/master
+
+  test:
+    needs: check
+    uses: ./.github/workflows/build.yml
+
+  publish:
+    needs: test
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write  # for prefix.dev Trusted Publishing
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: prefix-dev/setup-pixi@v0.11.3
+        with:
+          pixi-version: v0.84.1
+          environments: release
+          cache: true
+
+      - name: Build the conda packages
+        run: pixi run build-conda
+
+      - name: Upload the conda packages
+        uses: actions/upload-artifact@v4
+        with:
+          name: conda-packages
+          path: dist/*.conda
+
+      # Only the main repository is a trusted publisher of the channel
+      - name: Publish the conda packages to prefix.dev
+        if: github.repository_owner == 'Auto-Mech'
+        run: pixi run publish-conda
+
+  release:
+    needs: publish
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write  # to create the GitHub release
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Download the conda packages
+        uses: actions/download-artifact@v4
+        with:
+          name: conda-packages
+          path: dist/
+
+      # The static executables that the test job built and tested
+      - name: Download the static executables
+        uses: actions/download-artifact@v4
+        with:
+          name: mess-static-linux-64
+          path: mess-static/
+
+      - name: Archive the static executables
+        run: |
+          name="mess-static-${GITHUB_REF_NAME#v}-linux-64"
+          mv mess-static "$name"
+          chmod +x "$name"/*  # artifacts do not keep file permissions
+          tar -czf "dist/$name.tar.gz" "$name"
+
+      - name: Extract release notes
+        id: extract-release-notes
+        uses: ffurrer2/extract-release-notes@v2
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@v2
+        with:
+          tag_name: ${{ github.ref_name }}
+          body: ${{ steps.extract-release-notes.outputs.release_notes }}
+          files: |
+            dist/*.conda
+            dist/*.tar.gz

CHANGELOG.md

@@ -0,0 +1,36 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
+Versions are `YYYY.M.N`, where `N` counts the releases within the month.
+
+## [Unreleased]
+
+### Added
+
+- The `mess` conda package: the executables linked against conda-forge's ILP64 OpenBLAS and GSL.
+- Releases: a version tag builds and tests both packages, publishes them, and makes a GitHub release with the packages and a tarball of the static executables.
+
+### Changed
+
+- `mess-static` is built from source with CMake, instead of repackaging prebuilt executables. The executables are `mess`, `messpf` and `messabs`, and their output for the examples is unchanged.
+- `mess` and `mess-static` share one version.
+- The packages are published to the [`automech`](https://prefix.dev/channels/automech) channel on prefix.dev. The `auto-mech` channel on anaconda.org keeps the earlier `mess-static` packages and gets no new ones.
+- `examples/mess.inp` sets `WithCRM`, which its radiative oscillators need.
+
+### Removed
+
+- The `gumbo` executable from `mess-static`: its example input (`examples/messsym.inp`) does not run, so it cannot be tested.
+
+## [2026.2.4] - 2026-02-04
+
+- `mess-static` on anaconda.org, with executables built from the source of that date.
+
+## [2025.9.0] - 2025-09-25
+
+- `mess-static` on anaconda.org, packaged with Pixi.
+
+## [2024.5.16] - 2024-05-16
+
+- `mess-static` on anaconda.org, the first conda package of the static executables.

README.md

@@ -9,11 +9,26 @@ rate coefficients for complex-forming reactions via solution of the one-dimensio
 
 ## Installation
 
-The Auto-Mech channel provides fully static executables that run on any x86-64 Linux, with no runtime dependencies:
+The [`automech`](https://prefix.dev/channels/automech) channel on prefix.dev provides two conda packages with the same executables (`mess`, `messpf`, `messabs`).
+Install only one of them.
+
+`mess-static` has fully static executables that run on any x86-64 Linux, with no runtime dependencies:
+```
+conda install -c https://repo.prefix.dev/automech mess-static
+```
+In a [Pixi](https://pixi.sh) workspace:
+```
+pixi workspace channel add https://repo.prefix.dev/automech
+pixi add mess-static
+```
+`mess` is linked against the conda-forge libraries (OpenBLAS, GSL), so it also needs the `conda-forge` channel:
 ```
-conda install -c auto-mech mess-static
+conda install -c https://repo.prefix.dev/automech -c conda-forge mess
 ```
-They are also attached to each run of the GitHub Actions workflow (artifact `mess-static-linux-64`).
+The static executables are also attached to each [GitHub release](https://github.com/Auto-Mech/MESS/releases) as a tarball, for systems without conda.
+The changes in each release are listed in [`CHANGELOG.md`](CHANGELOG.md).
+
+The `auto-mech` channel on anaconda.org keeps the `mess-static` packages up to version 2026.2.4 and gets no new ones.
 
 ## Building from source
 
@@ -43,6 +58,21 @@ Options:
 - `MESS_BLAS_SUFFIX`: the suffix on the library's BLAS/LAPACK symbol names, if any. For example, `64_` for OpenBLAS built with `SYMBOLSUFFIX=64_`, like conda-forge's `libopenblas64_.so`. Check with `nm -D <library> | grep dsyev`. The static archive `libopenblas64_.a` has no suffix.
 - `MESS_STATIC` (default `OFF`): link fully static executables.
 
+## Releasing
+
+`mess` and `mess-static` share one version, `YYYY.M.N`, where `N` counts the releases within the month, starting from 0.
+To release, from an up-to-date `master` of this repository:
+1. List the changes to the source since the last release:
+   ```
+   git log --no-merges $(git describe --tags --abbrev=0)..HEAD -- src examples
+   ```
+2. Describe them under `[Unreleased]` in `CHANGELOG.md`, and commit.
+3. Run `pixi run release YYYY.M.N` (for example, `pixi run release 2026.11.0`).
+   This updates the version and the changelog, then commits, tags and pushes.
+
+The tag starts the release workflow (`.github/workflows/release.yml`), which builds and tests both packages, publishes them to the `automech` channel, and makes a GitHub release.
+`pixi run version` shows the current version.
+
 ## Reference
 
 See Y. Georgievskii, J. A. Miller, M. P. Burke, and S. J. Klippenstein,