Re: [gentoo-dev] Dangerous features in portage

[Jean-Michel Smith]

On Tuesday 29 October 2002 07:23 am, Paul de Vrieze wrote:

> The problem is downgrading. If you have had installed say libfoo-1.1. Now
> the developers find out that libfoo-1.1 is seriously broken. As a
> consequence, libfoo-1.1 is masked, and libfoo-1.0 is the newest. If you now
> do an emerge -u libfoo the old version is installed. But if libfoo-1.0
> allready was installed it doesn't get installed. The installation of
> libfoo-1.0 is not complete though, because libfoo-1.1 overwrites many of
> its files. Now with an emerge clean libfoo-1.1 is removed, as a consequence
> libfoo-1.0 is crippled and libfoo-1.1 is removed. An emerge clean after the
> upgrade to libfoo-1.1 would have stopped this. This is so the reason that
> emerge now performs an autoclean.

What about situations where you want to keep multiple versions of a shared 
library (that is, after all, one of the nice features of UNIX over, say, 
Windows)?  For example, you may have software that is compiled against an 
older, incompatible version of imlib (or worse, 3rd party binaries you can't 
recompile).

emerge clean nukes the old installation, and while the system is now no longer 
crufty it is also incompatible with that application.  I've seen this kino 
(before the new version came out) and dvlib, for example, and I'm sure there 
are other situations as well.

Jean.