[takeda]

> 1) Package collisions e.g. If I want to install a new custom build of python it replaces the host version and everything may break. The python3 v python2.6 problem.

I'm sorry, but you hit my pet peeve when you used python as example. Python was written in a way that you can have multiple versions installed side by side and they all can work without problem. If you have a python3 package that is uninstalling python2.6 then its author screwed something up and I would be afraid to use it at all.

> 2) Dependency namespacing. e.g. If I want rely on a non-official mirror to ship me whizbang project X they could also replace my libc by adding it to the repo because the names and versions collide.

Is that still an issue? Zypper in OpenSuSE is quite smart and for each package it remember which repo it is from. It tries to satisfy dependencies without changing vendor, and prompts if only way to satisfy dependencies is to change vendor.

That said if an application requires different version of glibc much better would be to compile it statically, but even then glibc supposed to match your kernel version so you're still risking some incompatibilities.

[XorNot]

Static glibc doesn't work anymore. If you need the internet then you'll be pulling in the nss plugins anyway.