Right way to switch to python 2.7 default

[Mayuresh <mayuresh%acm.org@localhost>]

I tried building some packages that complained of dependencies for py27
versions - py27-cairo for one.

Tried setting PYTHON_VERSION_DEFAULT to 26 as most existing packages are
built with 26, though for some of the packages this did not solve the
problem (although 26 was given as acceptable version in their make files).

Instead of trying to pull on with 26, thought I should rebuild packages
with 27 as some packages might start insisting on 27 is what appeared from
above.

If I try to rebuild, make install/update reports PLIST conflicts with py26
version of the package.

Trying to manually delete the py26 version throws lots of dependencies.
It's looking daunting to rebuild all those.

What is a good recipe for this situation - or is the only way to rebuild
everything that transitively depended on python26?

Mayuresh.