Bug#672552: kdelibs5-dev: PythonMacros.cmake breaks with Python 3

[Colin Watson <cjwatson@ubuntu.com>]

Package: kdelibs5-dev
Version: 4:4.7.4-4
Severity: normal
User: ubuntu-devel@lists.ubuntu.com
Usertags: origin-ubuntu quantal

PythonMacros.cmake assumes that byte-compiling any .py file will result
in a .pyc file in the current directory.  This breaks with Python 3,
which creates it in a __pycache__ subdirectory instead.

Gentoo carries a patch to allow suppressing this with an environment
variable:

  http://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/kde-base/kdelibs/files/kdelibs-4.6.3-bytecode.patch?view=markup
  https://bugs.gentoo.org/show_bug.cgi?id=372407

This would make a degree of sense for Debian as well since dh_python2
removes .pyc files anyway, so it's just a waste of time to byte-compile
them during package builds.  However, it would be nice if this macro
were smart enough to handle __pycache__ in the Python 3 case as well.

Thanks,

-- 
Colin Watson                                       [cjwatson@ubuntu.com]