Add comprehensive release process documentation

README.md

@@ -127,6 +127,10 @@ CTRL-D
 
 
 
+## For Maintainers
+
+- [Release Process](RELEASE.md) - How to create new releases
+
 ## Attribution
 
 If you make use of this code, please cite:

RELEASE.md

@@ -0,0 +1,115 @@
+# PTMCMCSampler Release Process
+
+**Status**: Manual release process (requires GitHub release + conda feedstock update)
+
+## Prerequisites
+- Maintainer access to [nanograv/PTMCMCSampler](https://github.com/nanograv/PTMCMCSampler)
+- Maintainer access to [conda-forge/ptmcmcsampler-feedstock](https://github.com/conda-forge/ptmcmcsampler-feedstock)
+- PyPI credentials configured in GitHub secrets (`PYPI_USERNAME`, `PYPI_PASSWORD`). Current maintainers know about this, but should be set up properly already.
+
+## Release Steps
+
+### 1. Prepare Release
+```bash
+# Ensure main branch is up to date
+git checkout master
+git pull origin master
+
+# Run tests locally
+make test
+
+# Check that all CI tests are passing on GitHub
+# Visit: https://github.com/nanograv/PTMCMCSampler/actions
+```
+
+### 2. Create Git Tag
+```bash
+# Create and push the git tag
+git tag v2.1.3
+git push origin v2.1.3
+```
+
+### 3. Create GitHub Release
+1. Go to [PTMCMCSampler releases](https://github.com/nanograv/PTMCMCSampler/releases)
+2. Click "Create a new release"
+3. Choose the tag version you just created (e.g., `v2.1.3`)
+4. Set release title (e.g., `v2.1.3`)
+5. Add release notes describing changes
+6. Click "Publish release"
+
+### 4. Automated PyPI Upload
+- GitHub Actions will automatically:
+  - Run tests across Python 3.8-3.11 and Ubuntu/macOS
+  - Build source distribution and wheel
+  - Test the built packages (`make test-sdist`, `make test-wheel`)
+  - Upload to PyPI using stored credentials
+
+### 5. Update Conda Feedstock (Semi-Automated)
+**⚠️ IMPORTANT: Wait for PyPI package to be available first!**
+
+1. **Wait for PyPI upload to complete** (usually 5-10 minutes after GitHub release)
+   - Check [PyPI package page](https://pypi.org/project/ptmcmcsampler/) for your new version
+   - Verify the package files are downloadable
+
+2. **Wait for conda-forge bot PR** (usually 30 minutes after PyPI release)
+   - The `regro-cf-autotick-bot` will automatically create a PR
+   - Go to [ptmcmcsampler-feedstock](https://github.com/conda-forge/ptmcmcsampler-feedstock) and look for the bot PR
+   - The bot will have already updated version number and SHA256 hash
+
+3. **Modify the bot's PR (if needed)**:
+   - Clone the [ptmcmcsampler-feedstock](https://github.com/conda-forge/ptmcmcsampler-feedstock) repository
+   - Check out the bot's branch (usually named like `2.1.4_ha7682d`)
+   - Make any necessary fixes to `recipe/meta.yaml` (if needed)
+   - Commit and push directly to the bot's branch
+
+4. **Add rerender comment**:
+   - Add this exact comment to the PR: `@conda-forge-admin, please rerender`
+   - Wait for automated rerendering to complete
+
+5. **Self-merge when ready**:
+   - Verify all checks pass (linting, rerendering)
+   - As a maintainer, merge the PR yourself
+   - No external review required for routine releases
+
+6. **Wait for conda package** (usually 1-2 hours after PR is merged)
+   - Check [conda-forge page](https://anaconda.org/conda-forge/ptmcmcsampler) for availability
+
+**Fallback if bot doesn't create PR within 1 hour:**
+- Manually update `recipe/meta.yaml` with the new version and SHA256 hash from [PyPI](https://pypi.org/project/ptmcmcsampler/)
+- Create a PR to the feedstock as described in the [conda-forge documentation](https://conda-forge.org/docs/maintainer/updating_pkgs.html)
+
+**Common Build Issues:**
+- **Python version compatibility**: If build fails for new Python versions (e.g., 3.14), add `--no-build-isolation` to the pip install command in `meta.yaml`
+- **setuptools errors**: Use `--no-build-isolation` to use conda-forge's setuptools instead of PyPI's
+
+## Timing Considerations
+
+### PyPI Package Availability
+- **Upload time**: 5-10 minutes after GitHub release is published
+- **Verification**: Check [PyPI package page](https://pypi.org/project/ptmcmcsampler/) for your version
+- **SHA256 hash**: Available immediately after upload completes (at the tar.gz download)
+
+### Conda Package Availability  
+- **Feedstock PR**: Submit after PyPI package is available
+- **Build time**: 1-2 hours after feedstock PR is merged
+- **Verification**: Check [conda-forge page](https://anaconda.org/conda-forge/ptmcmcsampler)
+
+## Version Management
+- Uses `setuptools_scm` - version automatically generated from git tags
+- No manual version file updates needed
+- Version is written to `PTMCMCSampler/version.py` automatically
+
+## Troubleshooting
+- **PyPI upload fails**: Check GitHub secrets are configured correctly
+- **Conda build fails**: Check dependencies in `meta.yaml` are up to date
+- **Tests fail**: Ensure all dependencies are installed locally before release
+
+## Release Checklist
+- [ ] All tests passing on GitHub Actions
+- [ ] Release notes prepared
+- [ ] Git tag created and pushed
+- [ ] GitHub release created
+- [ ] PyPI upload successful (check [PyPI page](https://pypi.org/project/ptmcmcsampler/))
+- [ ] Conda-forge bot PR created (wait ~30 minutes)
+- [ ] Conda feedstock PR merged (self-merge when checks pass)
+- [ ] Conda package available (check [conda-forge page](https://anaconda.org/conda-forge/ptmcmcsampler))