Bump version: v4.2.1

README.md

@@ -97,7 +97,7 @@ jobs:
       - uses: actions/setup-python@v6
 
       - name: Install cibuildwheel
-        run: python -m pip install cibuildwheel==4.2.0
+        run: python -m pip install cibuildwheel==4.2.1
 
       - name: Build wheels
         run: python -m cibuildwheel --output-dir wheelhouse
@@ -238,6 +238,15 @@ Changelog
 
 <!-- [[[cog from readme_changelog import mini_changelog; print(mini_changelog()) ]]] -->
 
+### v4.2.1
+
+_5 September 2026_
+
+- 🐛 Respects the NuGet package sources configured on the machine when installing CPython on Windows, instead of always falling back to nuget.org (#2966)
+- 🐛 Fixes a `NameError` on Pyodide when an already-compatible wheel was reused, which made the test step fail (#2968)
+- 🛠 Updates the Android Python versions, and the Android testbed's Gradle version, making it compatible with Java 25 (#2962)
+- 🛠 Updates dependencies including CPython 3.15.0rc2 (#2965, #2970, #2976, #2981, #2985)
+
 ### v4.2.0
 
 _4 August 2026_
@@ -340,18 +349,7 @@ See @henryiii's [release post](https://iscinumpy.dev/post/cibuildwheel-4-0-0/) f
 - 📚 Links back to source in docs (#2806)
 - 📚 Removes outdated numpy info (#2855)
 
-
-### v3.4.1
-
-_2 April 2026_
-
-- ⚠️ Building for the experimental CPython 3.13 free-threading variant is now deprecated. That functionality will be removed in the next minor release. The [`enable`](https://cibuildwheel.pypa.io/en/stable/options/#enable) option `cpython-freethreading` is therefore also deprecated. Builds specifying `enable = "all"` no longer select `cpython-freethreading`. CPython 3.14 free-threading support remains available without the `enable` flag. (#2787)
-- 🐛 iOS builds will no longer skip `repair-wheel-command` if it's defined in config (#2761)
-- 🐛 Fix bug causing `uv` to fail when environments define PYTHON_VERSION or UV_PYTHON, conflicting with our venvs (#2795)
-- ✨ cibuildwheel prints the selected build identifiers at the start of the build. (#2785)
-- 🔐 The GitHub Action now references other actions with a full SHA (#2744)
-
-<!-- [[[end]]] (sum: fEuiF50wvg) -->
+<!-- [[[end]]] (sum: 0zxqpn7F3B) -->
 
 ---
 

cibuildwheel/__init__.py

@@ -1 +1 @@
-__version__ = "4.2.0"
+__version__ = "4.2.1"

docs/changelog.md

@@ -5,6 +5,15 @@ ref: changelog
 
 # Changelog
 
+### v4.2.1
+
+_5 September 2026_
+
+- 🐛 Respects the NuGet package sources configured on the machine when installing CPython on Windows, instead of always falling back to nuget.org (#2966)
+- 🐛 Fixes a `NameError` on Pyodide when an already-compatible wheel was reused, which made the test step fail (#2968)
+- 🛠 Updates the Android Python versions, and the Android testbed's Gradle version, making it compatible with Java 25 (#2962)
+- 🛠 Updates dependencies including CPython 3.15.0rc2 (#2965, #2970, #2976, #2981, #2985)
+
 ### v4.2.0
 
 _4 August 2026_

docs/faq.md

@@ -158,7 +158,7 @@ There are two suggested methods for keeping cibuildwheel up to date that instead
 If you use GitHub Actions for builds, you can use cibuildwheel as an action:
 
 ```yaml
-uses: pypa/cibuildwheel@v4.2.0
+uses: pypa/cibuildwheel@v4.2.1
 ```
 
 This is a composite step that just runs cibuildwheel using pipx. You can set command-line options as `with:` parameters, and use `env:` as normal.
@@ -183,7 +183,7 @@ The second option, and the only one that supports other CI systems, is using a `
 
 ```bash
 # requirements-cibw.txt
-cibuildwheel==4.2.0
+cibuildwheel==4.2.1
 ```
 
 Then your install step would have `python -m pip install -r requirements-cibw.txt` in it. Your `.github/dependabot.yml` file could look like this:
@@ -402,7 +402,7 @@ Solutions to this vary, but the simplest is to use pipx:
 # most runners have pipx preinstalled, but in case you don't
 python3 -m pip install pipx
 
-pipx run cibuildwheel==4.2.0 --output-dir wheelhouse
+pipx run cibuildwheel==4.2.1 --output-dir wheelhouse
 pipx run twine upload wheelhouse/*.whl
 ```
 

examples/azure-pipelines-minimal.yml

@@ -6,7 +6,7 @@ jobs:
     - bash: |
         set -o errexit
         python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==4.2.0
+        pip3 install cibuildwheel==4.2.1
       displayName: Install dependencies
     - bash: cibuildwheel --output-dir wheelhouse .
       displayName: Build wheels
@@ -20,7 +20,7 @@ jobs:
     - bash: |
         set -o errexit
         python3 -m pip install --upgrade pip
-        python3 -m pip install cibuildwheel==4.2.0
+        python3 -m pip install cibuildwheel==4.2.1
       displayName: Install dependencies
     - bash: cibuildwheel --output-dir wheelhouse .
       displayName: Build wheels
@@ -34,7 +34,7 @@ jobs:
     - bash: |
         set -o errexit
         python -m pip install --upgrade pip
-        pip install cibuildwheel==4.2.0
+        pip install cibuildwheel==4.2.1
       displayName: Install dependencies
     - bash: cibuildwheel --output-dir wheelhouse .
       displayName: Build wheels

examples/circleci-minimal.yml

@@ -11,7 +11,7 @@ jobs:
       - run:
           name: Build the Linux wheels.
           command: |
-            python3 -m pip install --user cibuildwheel==4.2.0
+            python3 -m pip install --user cibuildwheel==4.2.1
             cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/
@@ -28,7 +28,7 @@ jobs:
       - run:
           name: Build the Linux aarch64 wheels.
           command: |
-            python3 -m pip install --user cibuildwheel==4.2.0
+            python3 -m pip install --user cibuildwheel==4.2.1
             python3 -m cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/
@@ -44,7 +44,7 @@ jobs:
           name: Build the OS X wheels.
           command: |
             sudo softwareupdate --install-rosetta --agree-to-license  # for x86_64/universal2 tests
-            pip3 install cibuildwheel==4.2.0
+            pip3 install cibuildwheel==4.2.1
             cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/

examples/github-deploy.yml

@@ -53,7 +53,7 @@ jobs:
           persist-credentials: false
 
       - name: Build wheels
-        uses: pypa/[email protected].0
+        uses: pypa/[email protected].1
         env:
           CIBW_PLATFORM: ${{ matrix.platform || 'auto' }}
           CIBW_ARCHS: ${{ matrix.archs || 'auto' }}

examples/github-minimal.yml

@@ -17,7 +17,7 @@ jobs:
           persist-credentials: false
 
       - name: Build wheels
-        uses: pypa/[email protected].0
+        uses: pypa/[email protected].1
         # env:
         #   CIBW_SOME_OPTION: value
         #   ...

examples/github-pipx.yml

@@ -17,7 +17,7 @@ jobs:
           persist-credentials: false
 
       - name: Build wheels
-        run: pipx run cibuildwheel==4.2.0
+        run: pipx run cibuildwheel==4.2.1
 
       - uses: actions/upload-artifact@v4
         with:

examples/github-with-qemu.yml

@@ -23,7 +23,7 @@ jobs:
           platforms: all
 
       - name: Build wheels
-        uses: pypa/[email protected].0
+        uses: pypa/[email protected].1
         env:
           # configure cibuildwheel on Linux to build native archs ('auto'),
           # and to split the remaining architectures between the x86_64 and

examples/gitlab-minimal.yml

@@ -12,7 +12,7 @@ linux:
     DOCKER_TLS_CERTDIR: ""
   script:
     - curl -sSL https://get.docker.com/ | sh
-    - python -m pip install cibuildwheel==4.2.0
+    - python -m pip install cibuildwheel==4.2.1
     - cibuildwheel --output-dir wheelhouse
   artifacts:
     paths:
@@ -23,7 +23,7 @@ windows:
   before_script:
     - choco install python -y --allow-downgrade --version 3.12.4
     - choco install git.install -y
-    - py -m pip install cibuildwheel==4.2.0
+    - py -m pip install cibuildwheel==4.2.1
   script:
     - py -m cibuildwheel --output-dir wheelhouse --platform windows
   artifacts:
@@ -35,7 +35,7 @@ windows:
 macos:
   image: macos-14-xcode-15
   before_script:
-    - python3 -m pip install cibuildwheel==4.2.0
+    - python3 -m pip install cibuildwheel==4.2.1
   script:
     - python3 -m cibuildwheel --output-dir wheelhouse
   artifacts:

examples/gitlab-with-qemu.yml

@@ -14,7 +14,7 @@ linux:
     - curl -sSL https://get.docker.com/ | sh
     # Warning: This is extremely slow, be careful with how many wheels you build
     - docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
-    - python -m pip install cibuildwheel==4.2.0
+    - python -m pip install cibuildwheel==4.2.1
     # Assuming your CI runner's default architecture is x86_64...
     - cibuildwheel --output-dir wheelhouse --platform linux --archs aarch64
   artifacts:

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "cibuildwheel"
-version = "4.2.0"
+version = "4.2.1"
 description = "Build Python wheels on CI with minimal configuration."
 readme = "README.md"
 license = "BSD-2-Clause"