equery depends vs. emerge -pv --depclean <atom> (was: Re: [gentoo-user] MySql versus sqlite. Don't want sqlite anymore.)

[Daniel Pielmeier]

Dale schrieb am 17.11.2009 22:53:
>
> root@smoker / # equery depends sqlite
> [ Searching for packages depending on sqlite... ]
> app-pda/libopensync-0.22 (>=dev-db/sqlite-3)

If you have this package installed and want to keep it you are forced to
keep sqlite as it is a hard dependency. Meaning this package needs
sqlite and there is no alternative.

> app-portage/eix-0.17.0 (sqlite? >=dev-db/sqlite-3)

Here sqlite is optional via use flag. So you can get rid of the
dependency it by disabling the use flag.

> Those appear to be in the ebuild and MySql is not a option for
> replacement.  Is there a way?  I have already emerged these with the
> -sqlite and +mysql USE flag.  I notice something about sqlite3 in one of
> the ebuilds.  What is that?

The main reason why I respond to this post is that there are still a lot
of people which are using "equery depends", although it is known to
print false positive by not taking use flags into account. You have to
scan through the output and check if the use flag is activated which
pulls in the package you want to check. Like for eix in the above
example. Eix only depends on sqlite if the sqlite use flag is activated.
"Equery depends" lists it in any case (activated or not) as it doesn't
take the use flags into account.

A more convenient way to find out the correct reverse dependencies with
portage is "emerge -pv --depclean <atom>"[1]. Running only "emerge -pv
--depclean" checks the complete world and system set, but if you pass a
package to it only the reverse dependencies of the package in question
are examined.

[1] http://www.gentoo.org/proj/en/portage/doc/faq.xml

-- 
Daniel Pielmeier