Bug#1010595: Please make xsimd available on all platforms

[Ole Streicher]

Source: xsimd
Version: 7.6.0-2
Control: affects -1 src:pythran src:skimage
Control: block 1009431 by -1
Control: block 1010430 by -1

Dear maintainer,

xsimd provides a unique API for SIMD instructions among different 
processor architectures. Additionally to many specific architectures, 
there is also a fallback scalar option for unsupported architectures (as 
far as I interpret the headers).

Currently, xsimd-dev fails to build on armel, armhf, mips64el, mipsel, 
ppc64el, s390x (armhf is built with 8.0.3-1 on experimental).

xsimd-dev is build dependency of pythran, which makes pythran 
uninstallable on the platforms where xsimd-dev fails.

In turn, python3-pythran is a new build dependency of skimage (0.19.2). 
The current version of skimage (0.18.3) is now starting to collect RC 
bugs because of incompatibilities with newer pil and tifffile versions 
(#1009431, #1010430).

skimage is also one of the basic scientific Python packages which is 
expected to be available on all platforms.

Therefore, could I ask to provide xsimd-dev for all platforms, using the 
scalar fallback for unsupported CPUs?

Best regards

Ole