Fix Windows wheel build quoting, and stop it from blocking other platforms' releases

.github/workflows/python-package.yml

@@ -427,10 +427,17 @@ jobs:
     strategy:
       matrix:
         # Modern, supported runner images (ubuntu-20.04 was retired in 2025).
-        # macos-15-intel -> x86_64 wheels, macos-14 -> arm64 wheels,
-        # windows-2022 -> AMD64 wheels. Build config lives in
-        # pyproject.toml's [tool.cibuildwheel] (cp3*, auto64, Cython).
-        os: [ubuntu-latest, macos-15-intel, macos-14, windows-2022]
+        # macos-15-intel -> x86_64 wheels, macos-14 -> arm64 wheels. Build
+        # config lives in pyproject.toml's [tool.cibuildwheel] (cp3*, auto64,
+        # Cython).
+        #
+        # windows-2022 is deliberately not in this list: a failure on that leg
+        # fails the whole `build_wheels` job (matrix legs are ANDed together
+        # for job success, independent of fail-fast), and `publish` needs
+        # `build_wheels` -- so one broken Windows build blocks every
+        # platform's release, not just Windows' (see #790). Re-add it once
+        # Windows wheel builds have proven stable again.
+        os: [ubuntu-latest, macos-15-intel, macos-14]
     steps:
       - uses: actions/checkout@v4
         with:

pyproject.toml

@@ -175,7 +175,16 @@ skip = ["*musllinux*"]
 # unknown directives instead of failing, so a lower version here would quietly
 # produce extensions that re-enable the GIL -- see the note in
 # `[build-system].requires`.
-before-build = "pip install 'Cython>=3.1'"
+#
+# Double-quoted, not single-quoted: cibuildwheel runs `before-build` through
+# the native shell, which on windows-2022 is cmd.exe.  cmd.exe does not treat
+# single quotes as a quoting character, so `'Cython>=3.1'` left the `>`
+# exposed as its output-redirection operator -- the command ran as `pip
+# install 'Cython` with stdout redirected to a file literally named `3.1'`,
+# which fails with no Cython installed.  cmd.exe does honor double quotes, and
+# bash/zsh treat `"..."` as a quoted string too, so this is quoted correctly
+# on every platform cibuildwheel builds on here.
+before-build = 'pip install "Cython>=3.1"'
 
 manylinux-x86_64-image = "manylinux2014"
 manylinux-pypy_x86_64-image = "manylinux2014"