[gentoo-user] Re: equery depends vs. emerge -pv --depclean <atom>

[Dale]

Daniel Pielmeier wrote:
> 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
>
>

I do know, because I have read about it, that equery is not 100% 
accurate.  It is a starting point tho.  Is it that equery needs a bit of 
rewriting or is it just that hard to do when taking USE flags into account?

Since one of those has a hard dependency on sqlite, it would have to 
stay anyway.  May as well leave it for the rest too.  Here is the output 
of --depclean for sqlite:

root@smoker / # emerge -pv --depclean sqlite

Calculating dependencies... done!
  dev-db/sqlite-3.6.19 pulled in by:
    dev-util/subversion-1.6.5

 >>> No packages selected for removal by depclean
Packages installed:   1199
Packages in world:    109
Packages in system:   50
Required packages:    202
Number to remove:     0
root@smoker / #     

Going by that, I would *think* subversion is all that needs sqlite.  
Would that be correct?  Trying to have a learning moment here.  ;-)

It appears that subversion is needed by this:

root@smoker / # emerge -pv --depclean subversion

Calculating dependencies... done!
  dev-util/subversion-1.6.5 pulled in by:
    app-admin/eselect-python-99999999

 >>> No packages selected for removal by depclean
Packages installed:   1199
Packages in world:    109
Packages in system:   50
Required packages:    202
Number to remove:     0
root@smoker / #

That lead to this:

root@smoker / # emerge -pv --depclean eselect-python

Calculating dependencies... done!
  app-admin/eselect-python-99999999 pulled in by:
    app-admin/gam-server-0.1.10
    dev-java/java-config-2.1.9-r1
    dev-lang/python-2.6.2-r1
    dev-lang/python-3.1.1-r1
    dev-libs/libgamin-0.1.10-r2
    dev-libs/libxml2-2.7.3-r2
    dev-libs/libxslt-1.1.24-r1
    dev-util/subversion-1.6.5
    sys-apps/file-5.03
    sys-apps/portage-2.2_rc50

 >>> No packages selected for removal by depclean
Packages installed:   1199
Packages in world:    109
Packages in system:   50
Required packages:    202
Number to remove:     0
root@smoker / # 

So in the end, it appears that a few things "depend" on sqlite. 

Dale

:-)  :-)