Bug#887521: libkf5auth-bin-dev is not useful for cross compilation

[Helmut Grohne <helmut@subdivi.de>]

Package: libkf5auth-bin-dev
Version: 4:4.14.36-1
User: helmutg@debian.org
Usertags: rebootstrap
Control: affects -1 + src:kwalletmanager

The issue to be found here is very close to #887452. I'm not duplicating
my thoughts here. I'm going to start with the differences and head to
the conclusion.

kauth-gen-policy appears to be a tool for turning a text file in
qsettings format (similar to .ini) into an xml file. Both are textual,
so it seems like putting kauth-gen-policy into a Multi-Arch: foreign
package (like kconfig_compiler_kf5 in #887452). Thus we can draw the
same conclusion.

I think making libkf5auth-bin-dev Multi-Arch: foreign is the right
approach. For consistency with other packages, it should be renamed to
libkf5auth-dev-bin (optional). For the marking to be correct,
kauth-gen-policy needs to live on an architecture-independent path
(needs to be moved) and the .cmake files need to be moved to
libkf5auth-dev. The path in KF5AuthToolsTargets-debian.cmake needs to be
updated for the new location of kauth-gen-policy.

Can someone make that work? Or maybe support me in figuring how to
implement that?

Helmut