switch to flit build backend (#1863)

.github/workflows/tests.yaml

@@ -41,11 +41,6 @@ jobs:
           python-version: ${{ matrix.python }}
           cache: 'pip'
           cache-dependency-path: 'requirements/*.txt'
-      - name: update pip
-        run: |
-          pip install -U wheel
-          pip install -U setuptools
-          python -m pip install -U pip
       - name: cache mypy
         uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8
         with:

CHANGES.rst

@@ -7,6 +7,7 @@ Unreleased
 
 -   Use modern packaging metadata with ``pyproject.toml`` instead of ``setup.cfg``.
     :pr:`1793`
+-   Use ``flit_core`` instead of ``setuptools`` as build backend.
 
 
 Version 3.1.3

CONTRIBUTING.rst

@@ -107,12 +107,6 @@ First time setup
 
         > env\Scripts\activate
 
--   Upgrade pip and setuptools.
-
-    .. code-block:: text
-
-        $ python -m pip install --upgrade pip setuptools
-
 -   Install the development dependencies, then install Jinja in editable
     mode.
 

pyproject.toml

@@ -2,7 +2,7 @@
 name = "Jinja2"
 description = "A very fast and expressive template engine."
 readme = "README.rst"
-license = {text = "BSD-3-Clause"}
+license = {file = "LICENSE.rst"}
 maintainers = [{name = "Pallets", email = "[email protected]"}]
 classifiers = [
     "Development Status :: 5 - Production/Stable",
@@ -32,11 +32,24 @@ i18n = ["Babel>=2.7"]
 [project.entry-points."babel.extractors"]
 
 [build-system]
-requires = ["setuptools"]
-build-backend = "setuptools.build_meta"
+requires = ["flit_core<4"]
+build-backend = "flit_core.buildapi"
 
-[tool.setuptools.dynamic]
-version = {attr = "jinja2.__version__"}
+[tool.flit.module]
+name = "jinja2"
+
+[tool.flit.sdist]
+include = [
+    "docs/",
+    "examples/",
+    "requirements/",
+    "tests/",
+    "CHANGES.rst",
+    "tox.ini",
+]
+exclude = [
+    "docs/_build/",
+]
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]