Bug#915946: python-escript: FTBFS with openmpi >= 3.1.3-3 (multiarch)

[Logan Rosen]

Source: python-escript
Version: 5.2-3
Severity: serious
Tags: ftbfs
Justification: fails to build from source (but built successfully in the past)

Dear Maintainer,

python-escript currently fails to build from source against openmpi >=
3.1.3-3, since it made a change in that version to have the symlink be
/usr/include/$ma/openmpi instead of /usr/include/openmpi [1]. This is
causing the following failure [2]:

RuntimeError: mpi.h not found under /usr/include:
  File "/<<PKGBUILDDIR>>/SConstruct", line 496:
    env=checkOptionalLibraries(env)
  File "/<<PKGBUILDDIR>>/site_scons/dependencies.py", line 497:
    mpi_inc_path,mpi_lib_path=findLibWithHeader(env, env['mpi_libs'], 'mpi.h', env['mpi_prefix'], lang='c++')
  File "/<<PKGBUILDDIR>>/site_scons/site_init.py", line 44:
    raise RuntimeError('%s not found under %s'%(header,paths))
make[1]: *** [debian/rules:78: override_dh_auto_build] Error 2
make[1]: Leaving directory '/<<PKGBUILDDIR>>'
make: *** [debian/rules:30: build] Error 2
dpkg-buildpackage: error: debian/rules build subprocess returned exit status 2

Can you please look into making python-escript aware of the multiarch
path for openmpi?

Thanks,
Logan

[1] https://tracker.debian.org/news/1007552/accepted-openmpi-313-3-source-amd64-all-into-unstable/
[2] https://launchpadlibrarian.net/400657334/buildlog_ubuntu-disco-amd64.python-escript_5.2-3_BUILDING.txt.gz

-- System Information:
Debian Release: buster/sid
  APT prefers cosmic-updates
  APT policy: (500, 'cosmic-updates'), (500, 'cosmic-security'), (500, 'cosmic'), (400, 'cosmic-proposed'), (100, 'cosmic-backports')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.18.0-11-generic (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled