build wheel in nix script

this is mainly so that we have the commands written down outside of
github actions, so we can easily build a hotfix wheel locally

.github/workflows/release.yml

@@ -18,20 +18,8 @@ jobs:
           submodules: true
       - uses: DeterminateSystems/nix-installer-action@main
       - uses: DeterminateSystems/magic-nix-cache-action@main
-      - run: nix develop .#evap-dev --command bash -c <<EOF
-          set -ex
-          npm ci
-          ./manage.py compilemessages
-          ./manage.py scss --production
-          ./manage.py ts compile --fresh
-          EOF
-      - uses: actions/setup-python@v5
-        with:
-          python-version: '3.10'
-      - run: |
-          python3 -m venv venv
-          source venv/bin/activate
-          python -m pip install --upgrade build
-          python -m build
+      - run: nix run .#build-dist
+      - run: tar tvf dist/*.tar.gz
+      - run: unzip -l dist/*.whl
       - name: Publish package distributions to PyPI
         uses: pypa/gh-action-pypi-publish@release/v1

flake.nix

@@ -90,6 +90,24 @@
               done
             '';
           };
+
+          build-dist = pkgs.writeShellApplication {
+            name = "build-dist";
+            runtimeInputs = with pkgs; [ nodejs gettext git ];
+            text =
+              let
+                python-dev = self.devShells.${system}.evap-dev.passthru.venv;
+                python-build = self.packages.${system}.python3.withPackages (ps: [ ps.build ]);
+              in
+              ''
+                set -x
+                npm ci
+                ${python-dev}/bin/python ./manage.py compilemessages
+                ${python-dev}/bin/python ./manage.py scss --production
+                ${python-dev}/bin/python ./manage.py ts compile --fresh
+                ${python-build}/bin/python -m build
+              '';
+          };
         });
     };
 }