While Haiku usually brings Python with it so its license is available
in the merged licenses directory, this isn't declared as a dependency
anywhere and therefore "chance". Since we yet lack a way to declare this
dependency (for lack of a license entity), duplicate the Python license
in the ports requiring it to make them self-contained.
* Referring the current haiku version explicitly is not needed, since
the RequiresUpdater takes care of setting the version of Haiku used
for building a package.
- the magic is in --single-version-externally-managed to disable
those (easter) egg things...
cf.
https://wiki.debian.org/Python/FAQ#How_should_we_package_Python_eggs.3F
- --root is required so just pass /
- also, python must be called without any path, else it setuptools uses
it as an extra prefix for install... so we munge PATH and call python.
