On Tue, 2012-01-31 at 15:58 -0500, Bill Nottingham wrote: > James Antill (james@xxxxxxxxxxxxxxxxx) said: > > > [root@nostromo ~]# mv /bin /cow > > > [root@nostromo ~]# /cow/ln -s /cow /bin > > > [root@nostromo ~]# rpm -qf /cow/bash > > > bash-4.2.20-1.fc16.x86_64 > > > [root@nostromo ~]# rpm -qf /bin/bash > > > bash-4.2.20-1.fc16.x86_64 > > > > > > rpm should already handle this, no need for the provides. > > > > Good to see everyone still doesn't read what I write. > > > > As I said, rpm _does something_ to make the above work for -qf (the > > above even works if you inside /cow ... as long as the /bin symlink > > exists!). > > However, it _does not_ work, if you put the above in package > > provides/requires and try to install them. Eg. > > It does, in some cases. Which makes it even more fun. > > Take a system with /usr/bin/sdiff. > > ... > Name: cow > Summary: cow > Version: 1.0 > Release: 1 > URL: http://redhat.com/ > License: Moo > Requires: /bin/sdiff > ... > > root@nostromo x86_64]# rpm -ivh cow-1.0-1.x86_64.rpm --test > error: Failed dependencies: > /bin/sdiff is needed by cow-1.0-1.x86_64 > [root@nostromo x86_64]# mv /bin /cow > [root@nostromo x86_64]# /cow/ln /usr/bin -s /bin > [root@nostromo x86_64]# /cow/rpm -ivh cow-1.0-1.x86_64.rpm --test > Preparing... ########################################### [100%] IMO this is pretty crazy, because by changing the symlink back you've broken the prco constraints in the DB (but everything would verify as "correct"). It also seems like rpm is doing a _lot_ of work it doesn't need to do here, but who knows ... it looks pretty magic (and I'm scared to go find out why/how it's doing the above :). Cc'ing rpm maintainers for their opinion on what rpm is doing and why. > Yum installs the package as well. Yeh, if it asks rpm if something is installed which satisfies that and is told yes, it will. However ... yum currently caches file requires/providers from rpm (among other things). So it's very possible that yum doesn't "DTRT" when it has cached data saying diffutils owns /usr/bin/sdiff and not /bin/sdiff (but it might, because it's a negative failure). In general I think only a huge amount of pain can come from relying on this (and you can't install into this situation, easily). -- devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/devel
