A bit of discussion: Why don't we use a stage?

[Danny Pansters]

Building a bit upon the mythtv maintainer who had a problem with deinstall, I 
never understood why we don't first build and install into a stage and then 
install into the live system from that (like Gentoo Linux does and I think to 
great benifit in terms of subimitters). It's much easier to make maximum use 
of that particular software's possibilities before comitting it to the live 
file system, as you can intervene right there on the staged install. Upon 
install we also often treat ${WRKDIR}/<theport> as being the stage as it is.

I wonder, are there pressing reasons not to do that (apart from marginally 
more space needed)? Perhaps this is a stupid or bikeshed question but I've 
wondered about this several times. Do I imagine a bigger gain than there 
would be in reality?

Dan