Convert to nox for the build system

In preparation for converting Safir to a monorepo with multiple
PyPI modules, convert to nox for the build system and move the current
code to a directory named safir. This will hold the main `safir`
package.

.github/workflows/ci.yaml

@@ -53,12 +53,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Run tox
-        uses: lsst-sqre/run-tox@v1
+      - name: Run nox
+        uses: lsst-sqre/run-nox@v1
         with:
+          cache-dependency: "*/pyproject.toml"
+          nox-sessions: "typing test"
           python-version: ${{ matrix.python }}
-          tox-envs: "py,typing"
-          tox-plugins: "tox-uv"
 
   docs:
 
@@ -73,12 +73,12 @@ jobs:
       - name: Install Graphviz
         run: sudo apt-get install graphviz
 
-      - name: Run tox
-        uses: lsst-sqre/run-tox@v1
+      - name: Run nox
+        uses: lsst-sqre/run-nox@v1
         with:
-          python-version: "3.12"
-          tox-envs: "docs,docs-linkcheck"
-          tox-plugins: tox-uv
+          cache-dependency: "*/pyproject.toml"
+          nox-sessions: "docs docs-linkcheck"
+          python-version: ${{ env.PYTHON_VERSION }}
 
       # Only attempt documentation uploads for tagged releases and pull
       # requests from ticket branches in the same repository.  This avoids
@@ -113,6 +113,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           upload: false
+          working-directory: "safir"
 
   pypi:
 
@@ -135,3 +136,4 @@ jobs:
       - uses: lsst-sqre/build-and-publish-to-pypi@v2
         with:
           python-version: ${{ env.PYTHON_VERSION }}
+          working-directory: "safir"

.github/workflows/periodic-ci.yaml

@@ -30,12 +30,11 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Run tests in tox
-        uses: lsst-sqre/run-tox@v1
+      - name: Run tests in nox
+        uses: lsst-sqre/run-nox@v1
         with:
+          nox-sessions: "update-deps lint typing test"
           python-version: ${{ matrix.python }}
-          tox-envs: "lint,typing,py"
-          tox-plugins: "tox-uv"
           use-cache: false
 
       - name: Report status
@@ -58,12 +57,11 @@ jobs:
       - name: Install Graphviz
         run: sudo apt-get install graphviz
 
-      - name: Build docs in tox
-        uses: lsst-sqre/run-tox@v1
+      - name: Build docs in nox
+        uses: lsst-sqre/run-nox@v1
         with:
+          nox-sessions: "docs docs-linkcheck"
           python-version: ${{ env.PYTHON_VERSION }}
-          tox-envs: "docs,docs-linkcheck"
-          tox-plugins: tox-uv
           use-cache: false
 
       - name: Report status
@@ -91,6 +89,7 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           upload: false
+          working-directory: "safir"
 
       - name: Report status
         if: failure()

changelog.d/20240719_160937_rra_DM_45281_queue.md

@@ -0,0 +1,3 @@
+### Other changes
+
+- Safir is now built with [nox](https://nox.thea.codes/en/stable/index.html) instead of [tox](https://tox.wiki/).

docs/_rst_epilog.rst

@@ -9,6 +9,7 @@
 .. _HTTPX: https://www.python-httpx.org/
 .. _kubernetes_asyncio: https://github.com/tomplus/kubernetes_asyncio
 .. _mypy: https://www.mypy-lang.org
+.. _nox: https://nox.thea.codes/en/stable/
 .. _Phalanx: https://phalanx.lsst.io
 .. _pre-commit: https://pre-commit.com
 .. _Pydantic: https://docs.pydantic.dev/latest/
@@ -25,3 +26,4 @@
 .. _tox: https://tox.wiki/en/latest/
 .. _tox-docker: https://tox-docker.readthedocs.io/en/latest/
 .. _Uvicorn: https://www.uvicorn.org/
+.. _virtualenvwrapper: https://virtualenvwrapper.readthedocs.io/en/stable/

docs/dev/development.rst

@@ -21,19 +21,31 @@ Safir is developed by the LSST SQuaRE team.
 Setting up a local development environment
 ==========================================
 
-To develop Safir, create a virtual environment with your method of choice (like virtualenvwrapper) and then clone or fork, and install:
+Development of Safir should be done inside a virtual environment.
 
-.. code-block:: sh
+Nublado uses nox_ as its build system, which can manage a virtual environment for you.
+Run:
+
+.. prompt:: bash
+
+   nox -s venv-init
+
+The resulting virtual environment will be created in :file:`.venv`.
+Enable it by running :command:`source .venv/bin/activate`.
 
-   git clone https://github.com/lsst-sqre/safir.git
-   cd safir
-   make init
+Alternately, you can create a virtual environment with any other method of your choice (such as virtualenvwrapper_).
+If you use a different virtual environment, run the following command after you have enabled it:
 
-This init step does three things:
+.. prompt:: bash
 
-1. Installs Safir in an editable mode with its "dev" extra that includes test and documentation dependencies.
-2. Installs pre-commit and tox.
-3. Installs the pre-commit hooks.
+   nox -s init
+
+Either ``venv-init`` or ``init`` does the following:
+
+#. Installs build system dependencies in the virtual environment.
+#. Installs package dependencies, including test and documentation dependencies.
+#. Installs Safir packages in editable mode so that changes made to the Git checkout will be picked up by the virtual environment.
+#. Installs pre-commit hooks.
 
 You must have Docker installed and configured so that your user can start Docker containers in order to run the test suite.
 
@@ -45,14 +57,8 @@ Pre-commit hooks
 The pre-commit hooks, which are automatically installed by running the :command:`make init` command on :ref:`set up <dev-environment>`, ensure that files are valid and properly formatted.
 Some pre-commit hooks automatically reformat code:
 
-``seed-isort-config``
-    Adds configuration for isort to the :file:`pyproject.toml` file.
-
-``isort``
-    Automatically sorts imports in Python modules.
-
-``black``
-    Automatically formats Python code.
+``ruff``
+    Lint and reformat Python code and attempt to automatically fix some problems.
 
 ``blacken-docs``
     Automatically formats Python code in reStructuredText documentation and docstrings.
@@ -65,26 +71,36 @@ To proceed, stage the new modifications and proceed with your Git commit.
 Running tests
 =============
 
-To test the library, run tox_, which tests the library the same way that the CI workflow does:
+To run all Safir tests, run:
 
-.. code-block:: sh
+.. prompt:: bash
 
-   tox run
+   nox -s
 
-To see a listing of test environments, run:
+This tests the library in the same way that the CI workflow does.
+You may wish to run the individual sessions (``lint``, ``typing``, ``test``, ``docs``, and ``docs-linkcheck``) when iterating on a specific change.
+Consider using the ``-R`` flag when you haven't updated dependencies, as discussed below.
 
-.. code-block:: sh
+To see a listing of nox sessions:
 
-   tox list
+.. prompt:: bash
 
-tox will start a PostgreSQL container, which is required for some tests.
+   nox --list
 
-To run a specific test or list of tests, you can add test file names (and any other pytest_ options) after ``--`` when executing the ``py`` tox environment.
+To run a specific test or list of tests, you can add test file names (and any other pytest_ options) after ``--`` when executing the ``test`` nox session.
 For example:
 
-.. code-block:: sh
+.. prompt:: bash
+
+   nox -s test -- safir/tests/database_test.py
 
-   tox run -e py -- tests/database_test.py
+If you are interating on a specific test failure, you may want to pass the ``-R`` flag to skip the dependency installation step.
+This will make nox run much faster, at the cost of not fixing out-of-date dependencies.
+For example:
+
+.. prompt:: bash
+
+   nox -Rs test -- safir/tests/database_test.py
 
 .. _dev-build-docs:
 
@@ -95,12 +111,29 @@ Documentation is built with Sphinx_:
 
 .. _Sphinx: https://www.sphinx-doc.org/en/master/
 
-.. code-block:: sh
+.. prompt:: bash
 
-   tox run -e docs
+   nox -s docs
 
 The build documentation is located in the :file:`docs/_build/html` directory.
 
+Additional dependencies required for the documentation build should be added as development dependencies of the ``safir`` library, in :file:`safir/pyproject.toml`.
+
+Documentation builds are incremental, and generate and use cached descriptions of the internal Python APIs.
+If you see errors in building the Python API documentation or have problems with changes to the documentation (particularly diagrams) not showing up, try a clean documentation build with:
+
+.. prompt:: bash
+
+   nox -s docs-clean
+
+This will be slower, but it will ensure that the documentation build doesn't rely on any cached data.
+
+To check the documentation for broken links, run:
+
+.. code-block:: sh
+
+   nox -s docs-linkcheck
+
 .. _dev-change-log:
 
 Updating the change log
@@ -136,7 +169,7 @@ Style guide
 Code
 ----
 
-- The code style follows :pep:`8`, though in practice lean on Black and isort to format the code for you.
+- The code style follows :pep:`8`, though in practice lean on Ruff to format the code for you.
 
 - Use :pep:`484` type annotations.
   The ``tox run -e typing`` test environment, which runs mypy_, ensures that the project's types are consistent.