Stop using deprecated packages in CI (#630)

* Stop using deprecated packages in CI

pep517 has been deprecated for a long time and we don't need it anymore,
courtesy of importlib.metadata.

* News fragment

* Try a fake version to look at the output

* Silence pip version warnings

The default pip versions are good enought, nowadays.

* Add debug output & give better name

* Revert "Try a fake version to look at the output"

This reverts commit 3aadb6a.

.github/workflows/ci.yml

@@ -11,6 +11,9 @@ defaults:
   run:
     shell: bash
 
+env:
+  PIP_DISABLE_PIP_VERSION_CHECK: "1"
+
 jobs:
   build:
     name: ${{ matrix.task.name}} - ${{ matrix.os.name }} ${{ matrix.python.name }}
@@ -250,18 +253,15 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v4
       with:
-        python-version: 3.11
-
-    - name: Install dependencies
-      run: |
-        python -m pip install --upgrade pip
-        python -m pip install pep517
+        python-version: 3.12
 
     - name: Display structure of files to be pushed
       run: ls --recursive dist/
 
-    - name: Check matched tag version and branch version - on tag
-      run: python admin/check_tag_version_match.py "${{ github.ref }}"
+    - name: Ensure tag and package versions match.
+      run: |
+        python -Im pip install dist/*.whl
+        python -I admin/check_tag_version_match.py "${{ github.ref }}"
 
     - name: Publish to PyPI - on tag
       uses: pypa/gh-action-pypi-publish@a56da0b891b3dc519c7ee3284aff1fad93cc8598

admin/check_tag_version_match.py

@@ -1,15 +1,16 @@
 #
 # Used during the release process to make sure that we release based on a
-# tag that has the same version as the current twisted.__version.
+# tag that has the same version as the current packaging metadata.
 #
 # Designed to be conditionally called inside GitHub Actions release job.
 # Tags should use PEP440 version scheme.
 #
-# To be called as: admin/check_tag_version_match.py refs/tags/twisted-20.3.0
+# To be called as: admin/check_tag_version_match.py refs/tags/20.3.0
 #
+
 import sys
 
-import pep517.meta
+from importlib import metadata
 
 
 TAG_PREFIX = "refs/tags/"
@@ -18,7 +19,8 @@
     print("No tag check requested.")
     sys.exit(0)
 
-branch_version = pep517.meta.load(".").version
+pkg_version = metadata.version("towncrier")
+print(f"Package version is {pkg_version}.")
 run_version = sys.argv[1]
 
 if not run_version.startswith(TAG_PREFIX):
@@ -27,9 +29,9 @@
 
 run_version = run_version[len(TAG_PREFIX) :]  # noqa: E203
 
-if run_version != branch_version:
-    print(f"Branch is at '{branch_version}' while tag is '{run_version}'")
+if run_version != pkg_version:
+    print(f"Package is at '{pkg_version}' while tag is '{run_version}'")
     exit(1)
 
-print(f"All good. Branch and tag versions match for '{branch_version}'.")
+print(f"All good. Package and tag versions match for '{pkg_version}'.")
 sys.exit(0)

pyproject.toml

@@ -1,7 +1,5 @@
 [build-system]
-requires = [
-    "hatchling",
-]
+requires = ["hatchling"]
 build-backend = "hatchling.build"