It really must be literally 39.

jaraco · jaraco · commit 0dfbfb81c677 · 2021-12-29T13:19:59.000-05:00
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
@@ -35,7 +35,7 @@ jobs:
     strategy:
       matrix:
         python:
-        - 3.9
+        - 39
         platform:
         - windows-latest
     runs-on: ${{ matrix.platform }}
@@ -46,9 +46,9 @@ jobs:
         with:
           platform: x86_64
           packages: >-
-            python${{ matrix.python//.// }},
-            python${{ matrix.python//.// }}-devel,
-            python${{ matrix.python//.// }}-pytest,
+            python${{ matrix.python }},
+            python${{ matrix.python }}-devel,
+            python${{ matrix.python }}-pytest,
             gcc-core,
             gcc-g++,
             ncompress
