[arch-general] pacman's "Depends On"

[Aaron Caffrey]

On 23/04/15 at 04:18pm, Ralf Mardorf wrote:
>Hi :)
>
>if a dedicated version of a dependency is needed, some packages
>mention it, others don't.
>
>Firefox does not explicitly mention a version of libvpx
>
>$ pacman -Si firefox | grep On
>Depends On     : [snip] libvpx [snip]
>
>but it needs a dedicated version
>
>$ firefox
>XPCOMGlueLoad error for file /usr/lib/firefox/libxul.so:
>libvpx.so.2: cannot open shared object file: No such file or directory
>Couldn't load XPCOM.
>
>ffmpeg does mentions that a dedicated version is needed
>
>$ pacman -Si ffmpeg | grep On
>Depends On     : [snip] libvpx.so=2-64 [snip]
>
>IMO official packages should mention dedicated versions, since for
>users of a rolling release, there sometimes are good reasons to
>downgrade.
>
>I tried to build Firefox from ABS against the outdated version of libvpx
>that is needed and installed on my system, but that's another issue.
>
>Perhaps other packages are broken too and I get aware of it, at an
>inconvenient time.
>
>How can I figure out what packages depend on a dedicated version of
>another package?
>
>Regards,
>Ralf

Hello Ralf,

Maybe you should specify which packages to be ignored via 'IgnorePkg'
variable, here is the link
https://wiki.archlinux.org/index.php/Downgrading_packages#How_do_I_stop_pacman_from_upgrading_downgraded_packages.3F

Best regards,
Aaron Caffrey