dnf whatprovides and library files

[Matthew Miller]

On Wed, Jun 10, 2015 at 04:20:13AM -0400, Radek Holy wrote:
> BTW, RPM can do that:
> $ rpm --query --file /lib64/libXv.so.1.0.0
> So, if RPM tracks these symlinks and if it provides an API to get this information, DNF could do the magic at least for the installed packages. But maybe it could become even more confusing for users since "whatprovides" would sometimes find the package and sometimes not depending on whether the package is installed or not. Maybe printing a warning would be sufficient...

I believe RPM isn't tracking the symlink — it's just canonicalizing the
filename when you do the --query --file (or -qf). Easy to do _on_ the
system, not so good when you're asking about a non-existent file.

An approach a DNF plugin might take, though, would be to look at all
existing elements of the pathname and see if they can be canonicalized.
And it looks like python's `os.path.realpath()` actually works that
way, so you could just try calling that on any filenames passed to dnf
provides. However, I bet we are inconsistent and have some places on
the system where files are installed into a location under a symlink,
by _that_ name. So, perhaps best to just special-case the usrmove paths 
/bin, /sbin, /lib, and /lib64.

-- 
Matthew Miller
<mattdm at fedoraproject.org>
Fedora Project Leader