Ahh, forget repo fusion :-).

[Tom Horsley]

Just out of curiosity, how feasible do you think it might
be to give up on the overwhelmingly complex task of
making all 3rd party software installation compatible,
and instead make linux userland be able to install
multiple incompatible packages (heck, be able to install
both rpms and debs for that matter) in multiple "virtual
roots"?

It seems like adding a tree structure to the dynamic linker
and the ldconfig database could get most of this, so programs
loaded from the /alt/debian/usr/bin directory would first
load shared libs pointed at by the /alt/debian/etc/ldconfig
then fall back to /etc/ldconfig (just as a hypothetical
example).

Aside from allowing essentially any packages from any linux
distribution or repo to be loaded on one system, this same
technique could reduce the mind-shattering nonsense that
is the current multilib support for 32 and 64 bit by
simply taking the same approach to divide the system into
32 and 64 bit roots.

Just a wild idea, but I wonder what people think?