Warning: This is probably a noob question, I just replaced Debian on my Desktop with Funtoo...
Now I try to allow Python 2 and 3 to coexist peacefully. The main problem are the python_single_target_pythonX_X use flags. A lot of packages need exactly one of them specified. But some require Python 2 and some Python 3.
In /etc/portage/make.conf I specified
PYTHON_TARGETS="python2_7 python3_4" PYTHON_SINGLE_TARGET="python3_4"
If I add python2_7 as single target, some ebuilds start complaining about needing exacly one of the two but not both specified. But if I don't add python2_7, ebuilds that depend on Python 2 won't build. The only solution I found was to specify the use flag for every single application in /etc/portage/package.use like this:
But that's a lot of lines to add to that file and I figured there has to be a easier way to do this. I tried to find some documentation about Python on Gentoo but wasn't lucky.
When I try to install ports that depend on Python 2 or when I try to do a 'emerge -uND @world' I get this error:
The following REQUIRED_USE flag constraints are unsatisfied: python_single_target_python2_7