Bug#703868: libav: Internal error: found 2 (choice -> promotion) mappings for a single choice.

[Reinhard Tartler]

On Mon, Mar 25, 2013 at 6:55 AM, shirish शिरीष <shirishag75 at gmail.com> wrote:
> Source: libav
> Version: 6:9.4-1
> Severity: normal
>
> Dear Maintainer,
>         I was updating the system today and came across this :-
>
> $ sudo aptitude install libswscale2=6:9.4-1 libswscale-dev=6:9.4-1
> libavutil-dev=6:9.4-1 libavcodec-dev=6:9.4-1 libavutil52=6:9.4-1
> libavformat-dev=6:9.4-1 libavformat54=6:9.4-1 -y
> The following NEW packages will be installed:
>   libavcodec-extra-54{ab}
> The following packages will be upgraded:
>   libavcodec-dev libavformat-dev libavformat54 libavutil-dev
> libavutil52 libswscale-dev libswscale2
> 7 packages upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
> Need to get 6,876 kB of archives. After unpacking 7,697 kB will be used.
> The following packages have unmet dependencies:
>  libavcodec54 : Conflicts: libavcodec-extra-54 but 6:9.4-1 is to be installed.
>  libavcodec-extra-54 : Conflicts: libavcodec54 but 6:9.3-1 is installed.
> Internal error: found 2 (choice -> promotion) mappings for a single choice.
> Internal error: found 2 (choice -> promotion) mappings for a single choice.
> Internal error: found 2 (choice -> promotion) mappings for a single choice.
> Internal error: found 2 (choice -> promotion) mappings for a single choice.
> The following actions will resolve these dependencies:
>
>   Remove the following packages:
> 1)     libavcodec54
>
> The following NEW packages will be installed:
>   libavcodec-extra-54{a}
> The following packages will be REMOVED:
>   libavcodec54{a}
> The following packages will be upgraded:
>   libavcodec-dev libavformat-dev libavformat54 libavutil-dev
> libavutil52 libswscale-dev libswscale2
> 7 packages upgraded, 1 newly installed, 1 to remove and 0 not upgraded.
> Need to get 6,876 kB of archives. After unpacking 975 kB will be used.
>
> While I don't understand all the implications of the above upgrade,
> however I do understand that one of the packages is being removed
> while the other is taking it's place. I didn't find anything in the
> changelog as to why this is desirable. Also why it took one choice
> when it says there are two choices.
>
> Looking forward for more info. Maybe I did something wrong.

Besides having libavcodec54 being replaced with libavcodec-extra-54
(the latter is binary compatible with the former, but provides more
functionality, hence the "-extra-"), what exact problems do you
experience?

-- 
regards,
    Reinhard