# NumPy 1.21.4 Release Notes

The NumPy 1.21.4 is a maintenance release that fixes a few bugs discovered after 1.21.3. The most important fix here is a fix for the NumPy header files to make them work for both x86_64 and M1 hardware when included in the Mac universal2 wheels. Previously, the header files only worked for M1 and this caused problems for folks building x86_64 extensions. This problem was not seen before Python 3.10 because there were thin wheels for x86_64 that had precedence. This release also provides thin x86_64 Mac wheels for Python 3.10.

The Python versions supported in this release are 3.7-3.10. If you want to compile your own version using gcc-11, you will need to use gcc-11.2+ to avoid problems.

## Contributors

A total of 7 people contributed to this release. People with a “+” by their names contributed a patch for the first time.

- Bas van Beek

- Charles Harris

- Isuru Fernando

- Matthew Brett

- Sayed Adel

- Sebastian Berg

- 傅立业（Chris Fu） +

## Pull requests merged

A total of 9 pull requests were merged for this release.

- #20278: BUG: Fix shadowed reference of `dtype` in type stub

- #20293: BUG: Fix headers for universal2 builds

- #20294: BUG: `VOID_nonzero` could sometimes mutate alignment flag

- #20295: BUG: Do not use nonzero fastpath on unaligned arrays

- #20296: BUG: Distutils patch to allow for 2 as a minor version (!)

- #20297: BUG, SIMD: Fix 64-bit/8-bit integer division by a scalar

- #20298: BUG, SIMD: Workaround broadcasting SIMD 64-bit integers on MSVC…

- #20300: REL: Prepare for the NumPy 1.21.4 release.

- #20302: TST: Fix a `Arrayterator` typing test failure