[Numpy-discussion] Dropping 32-bit from macOS wheels (original) (raw)

Matthew Brett matthew.brett at gmail.com
Tue Aug 14 05:17:31 EDT 2018

Hi,

Short version:

We are planning to drop 32-bit compatibility from the numpy macOS wheels. This email is to ask for feedback.

Long version:

macOS has tooling to allow distribution of binaries that have objects for more than one architecture. These are called "fat" binaries, and they were useful when Macs could be PPC, 32-bit or 64-bit intel. Now of course, they are effectively all 64-bit Intel.

Amusingly enough, you can use the "lipo" command to operate on fat binaries. For example, system Python (at /usr/bin/python) is a fat binary, containing objects for 32 and 64-bit.

$ lipo -info /usr/bin/python Architectures in the fat file: /usr/bin/python are: i386 x86_64

It is possible to run Python in 32-bit mode with:

$ arch -i386 /usr/bin/python

Up until the last release of numpy, we have build fat (32 and 64 bit) binaries for numpy, so, if you do run Python in 32-bit mode, you can still import and use numpy. In the last release, I accidentally broke the 32-bit part of the build - see https://github.com/numpy/numpy/issues/11625 .

We could fix this, but we suspect that there are very few people still using 32-bit on macOS. If you do use it - please let us know, and we'll consider the options.

Cheers,

Matthew

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