Convert Python ports to FLAVORS.
Ports using USE_PYTHON=distutils are now flavored. They will
automatically get flavors (py27, py34, py35, py36) depending on what
versions they support.
There is also a USE_PYTHON=flavors for ports that do not use distutils
but need FLAVORS to be set. A USE_PYTHON=noflavors can be set if
using distutils but flavors are not wanted.
A new USE_PYTHON=optsuffix that will add PYTHON_PKGNAMESUFFIX has been
added to cope with Python ports that did not have the Python
PKGNAMEPREFIX but are flavored.
USES=python now also exports a PY_FLAVOR variable that contains the
(Only the first 15 lines of the commit message are shown above )
The port lists databases/py3-sqlite3 as dependency which does not exist. There
are individual python-sub-version ports though (devel/py3{4,5,6}-sqlite3).
Use PYTHON_SUFFIX to depend on requested version.
PR: 223514
Approved by: koobs (maintainer)
MFH: 2017Q4 (blanket)
