Bug#1105149: g-ir-scanner cross wrapper does not interact well with cross building Python extensions

[Helmut Grohne <helmut@subdivi.de>]

Package: gobject-introspection
Version: 1.84.0-1
X-Debbugs-Cc: debian-cross@lists.debian.org

I observed that zbar was not using qemu during g-ir-scanner and looked
into it. It turns out that I was patching it to export
_PYTHON_SYSCONFIGDATA_NAME as it would build a Python extension module.
That variable leaked into the part of the build where it runs
g-ir-scanner. It ended up calling the cross wrapper. Unfortunately,
there is a short cut "if sysconfig.get_config_var('MULTIARCH') ==
DEB_HOST_MULTIARCH". The left hand gets influenced by setting
_PYTHON_SYSCONFIGDATA_NAME and therefore the short cut is taken
disabling qemu.

Can we change this short cut to avoid this trap? Any suggestions for
how?

Thanks for considering

Helmut