Re: [gentoo-user] update problems

[Neil Bothwick]

On Sat, 19 Sep 2015 21:36:06 +0200, lee wrote:

> emerge -j 8 -a --update --newuse --deep --with-bdeps=y
> @world
>
>  * IMPORTANT: 4 news items need reading for repository 'gentoo'.
>  * Use eselect news read to view new items.
>
>
> These are the packages that would be merged, in order:
>
> Calculating dependencies... done!
>
> !!! Multiple package instances within a single package slot have been
> pulled !!! into the dependency graph, resulting in a slot conflict:
>
> dev-libs/boost:0
>
>   (dev-libs/boost-1.56.0-r1:0/1.56.0::gentoo, ebuild scheduled for
> merge) pulled in by (no parents that aren't satisfied by other packages
> in this slot)
>
>   (dev-libs/boost-1.55.0-r2:0/1.55.0::gentoo, ebuild scheduled for
> merge) pulled in by dev-libs/boost:0/1.55.0= required by
> (dev-libs/librevenge-0.0.2:0/0::gentoo, installed)
> ^^^^^^^^^^ (and 2 more with the same problem)
>
> dev-util/boost-build:0
>
>   (dev-util/boost-build-1.55.0:0/0::gentoo, installed) pulled in by
>     =dev-util/boost-build-1.55* required by
> (dev-libs/boost-1.55.0-r2:0/1.55.0::gentoo, ebuild scheduled for merge)
> ^
> ^^^^^
>
>   (dev-util/boost-build-1.56.0:0/0::gentoo, ebuild scheduled for merge)
> pulled in by =dev-util/boost-build-1.56* required by
> (dev-libs/boost-1.56.0-r1:0/1.56.0::gentoo, ebuild scheduled for merge)
> ^
> ^^^^^
>
> media-video/ffmpeg:0
>
>   (media-video/ffmpeg-2.6.3:0/54.56.56::gentoo, ebuild scheduled for
> merge) pulled in by (no parents that aren't satisfied by other packages
> in this slot)
>
>   (media-video/ffmpeg-2.2.14:0/52.55.55::gentoo, installed) pulled in by
>     media-video/ffmpeg:0/52.55.55=[vdpau] required by
> (media-libs/mlt-0.9.0:0/0::gentoo, installed)
> ^^^^^^^^^^^
These are unimportant, it is simply portage telling you it is not
updating some packages to the latest available and why. Personally, I
believe this sort of output should only be shown when using --verbose. 

> It may be possible to solve this problem by using package.mask to
> prevent one of those packages from being selected. However, it is also
> possible that conflicting dependencies exist such that they are
> impossible to satisfy simultaneously.  If such a conflict exists in
> the dependencies of two different packages, then those packages can
> not be installed simultaneously.
>
> For more information, see MASKED PACKAGES section in the emerge man
> page or refer to the Gentoo Handbook.
>
>
> !!! The ebuild selected to satisfy "sci-libs/hdf5" has unmet
> requirements.
> - sci-libs/hdf5-1.8.14-r1::gentoo USE="cxx fortran threads zlib -debug
> -examples -fortran2003 -mpi -static-libs -szip"
>
>   The following REQUIRED_USE flag constraints are unsatisfied:
>     threads? ( !cxx !fortran )

This is blocking you and the reason is given, if you have the threads
flag on, cxx and fortran must be off. You have both threads and cxx on
which won't work.

> Why can't we just update like we can with any other distribution but
> have to run into dependency problems all the time instead?

These aren't dependency problems, they are conflicting USE flags, a
situation that cannot arise with a binary distro. If you want the
flexibility that USE flags offer, you have to accept that not all
combinations will work together.

> What do I do when I need to update /right now/ and find myself being
> blocked with cryptic messages like the above that leave me stranded?

That's the real problem, that the messages are so cryptic. The solution
is simple, working out what needs to be done from the messages is not.

> Once I used 'emerge --sync', there is no way to turn it back to continue
> to be able to install software if needed when the update cannot be
> performed.  Updates simply need to work, there's no way around that.

You can always roll back by masking the updates if necessary, and the
old ebuilds are always available. Now that the tree is using git, it is
probably possibly to sync back to yesterday if you need to.


-- 
Neil Bothwick

WINDOWS: Will Install Needless Data On Whole System