On behalf of the NumPy team I am pleased to announce the release of NumPy 1.21.4. NumPy 1.21.4 is a maintenance release that fixes a few bugs discovered after 1.21.3. The most important fix here is 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. Note that there are *no* manylinux1 wheels, the needed CentOS 5 repos have gone missing. Make sure you upgrade your pip version if you have problems downloading the correct wheels.
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. Wheels can be downloaded from PyPI https://pypi.org/project/numpy/1.21.4/; source archives, release notes, and wheel hashes are available on Github https://github.com/numpy/numpy/releases/tag/v1.21.4. Linux users will need pip >= 0.19.3 in order to install manylinux2010 and manylinux2014 wheels. A recent version of pip is needed to install the universal2 macos wheels.
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