On Mon, Feb 08, 2010 at 11:29:28AM +1000, Allan McRae wrote: > >I find it extremely strange that updating a library > >removes the original - never seen this on any other > >distro. Nor is there any need to do this. > > We only package the latest stable versions of software and so very > rarely have multiple different versions of a library. Providing only the latest in the repos is OK, but erasing a previous version **with a different major version number** on a user's system surely isn't, as existing applications will depend on it. If I have /usr/lib/libpng.so -> libpng12.so /usr/lib/libpng12.so -> libpng12.so.12.0.0 /usr/lib/libpng12.so.12 -> libpng12.so.12.0.0 /usr/lib/libpng12.so.12.0.0 and installing a new app requires version 14, then the new situation should be /usr/lib/libpng.so -> libpng14.so /usr/lib/libpng12.so -> libpng12.so.12.0.0 /usr/lib/libpng12.so.12 -> libpng12.so.12.0.0 /usr/lib/libpng12.so.12.0.0 /usr/lib/libpng14.so -> libpng14.so.14.0.0 /usr/lib/libpng14.so.14 -> libpng14.so.14.0.0 /usr/lib/libpng14.so.14.0.0 which means that a previously installed app that expects libpng12.so or /usr/lib/libpng12.so.12 will still work. Replacing is allowed only if the major version number stays the same (which implies the lib will be compatible with the one it replaces). The only alternative to this is making sure that updated versions of all apps are made available as soon as the new library is used by any of them, and this is clearly impossible. I'm pretty sure that at the moment a system update or even complete fresh install including texlive, emacs and gnuplot will have the latter two not working. The most recent versions (as of writing) require different libraries. So, apparently there is no solution. Ciao, -- FA O tu, che porte, correndo si ? E guerra e morte !
