Bug#972394: likely cause: Python.h not found because of version mismatch 3.8 vs 3.9

[Adrian Bunk]

Control: retitle -1 siconos FTBFS with more than one supported python3 version

On Mon, Oct 19, 2020 at 11:38:42PM +0200, Markus Koschany wrote:
> 
> I built siconos in a clean chroot environment. The recent rebuild of
> siconos also shows build failures
> 
> https://buildd.debian.org/status/package.php?p=siconos
> 
> I don't think it's specific to my environment.

You need something like python3-dev -> python3-all-dev in the build 
dependencies.

The next problem is what it builds - it then builds for the highest 
version only, not for the default version.

This bug could be solved by either adjusting the build dependencies
and the build to build for all supported python3 versions, or by fixing 
whatever in the build system does not use the default version.

> Cheers,
> 
> Markus

cu
Adrian