[arch-general] Why couldn't pacman resolve the dependency?

[Ralf Mardorf]

Hi,

the problem could be solved by installing the problematic dependency
first, but why couldn't pacman -Syu not resolve the dependency?

This is what happened:

$ pacman -Si perl-cpanplus perl-package-constants
Repository     : community
Name           : perl-cpanplus
Version        : 0.9152-2
Depends On     : perl  perl-log-message  perl-archive-extract  perl-term-ui  perl-log-message-simple
                 perl-module-pluggable  perl-object-accessor  perl-package-constants
Optional Deps  : None
Conflicts With : None
Replaces       : None

Repository     : community
Name           : perl-package-constants
Version        : 0.06-1
Depends On     : perl
Optional Deps  : None
Conflicts With : None
Replaces       : None

$ date;sudo pacman -Syu
Sun Jun 28 17:44:01 CEST 2015
:: Synchronizing package databases...
 core is up to date
 extra is up to date
 community is up to date
 multilib is up to date
 archaudio-production is up to date
:: Starting full system upgrade...
warning: ardour: ignoring package upgrade (4.0-2 => 4.1-1)
warning: audacity: local (2.1.0-2) is newer than extra (2.1.0-1)
warning: clthreads: local (2.4.0-5) is newer than community (2.4.0-1)
warning: gvfs: local (2013.08.18-1) is newer than extra (1.24.1-2)
warning: hunspell-en: ignoring package upgrade (7.1-3 => 2015.05.18-4)
warning: libfishsound: local (1.0.0-2) is newer than community (1.0.0-1)
warning: linux-rt: ignoring package upgrade (4.0.4_rt1-1 => 4.0.5_rt4-1)
warning: linux-rt-docs: ignoring package upgrade (4.0.4_rt1-1 => 4.0.5_rt4-1)
warning: linux-rt-headers: ignoring package upgrade (4.0.4_rt1-1 => 4.0.5_rt4-1)
warning: linux-rt-lts: ignoring package upgrade (3.10.61_rt65-1 => 3.18.16_rt13-1)
warning: linux-rt-lts-docs: ignoring package upgrade (3.10.61_rt65-1 => 3.18.16_rt13-1)
warning: linux-rt-lts-headers: ignoring package upgrade (3.10.61_rt65-1 => 3.18.16_rt13-1)
warning: ignoring package replacement (mate-calc-1.8.0-2 => galculator-gtk2-2.1.3-3)
warning: meterbridge: local (0.9.2-5) is newer than community (0.9.2-1)
warning: pulseaudio: local (2013.08.18-1) is newer than extra (6.0-2)
warning: sylpheed: local (3.4.2-20141124) is newer than community (3.4.2-1)
warning: virtualbox: ignoring package upgrade (4.3.12-1 => 4.3.28-1)
warning: virtualbox-guest-iso: ignoring package upgrade (4.3.12-1 => 4.3.28-1)
warning: virtualbox-host-dkms: ignoring package upgrade (4.3.12-1 => 4.3.28-1)
warning: zita-alsa-pcmi: ignoring package upgrade (0.2.0-1 => 0.2.0-2)
warning: zita-resampler: ignoring package upgrade (1.3.0-2 => 1.3.0-3)
resolving dependencies...
looking for conflicting packages...
error: failed to prepare transaction (could not satisfy dependencies)
:: perl-cpanplus: requires perl-package-constants

$ sudo pacman -S perl-package-constants
resolving dependencies...
looking for conflicting packages...

Packages (1) perl-package-constants-0.06-1

Total Download Size:   0.00 MiB
Total Installed Size:  0.00 MiB

:: Proceed with installation? [Y/n] 
:: Retrieving packages ...
 perl-package-constants-0.06-1-any           4.7 KiB  1581K/s 00:00 [--------------------------------------] 100%
(1/1) checking keys in keyring                                      [--------------------------------------] 100%
(1/1) checking package integrity                                    [--------------------------------------] 100%
(1/1) loading package files                                         [--------------------------------------] 100%
(1/1) checking for file conflicts                                   [--------------------------------------] 100%
(1/1) checking available disk space                                 [--------------------------------------] 100%
(1/1) installing perl-package-constants                             [--------------------------------------] 100%

$ date;sudo pacman -Syu
Sun Jun 28 17:47:47 CEST 2015
:: Synchronizing package databases...
 core is up to date
 extra is up to date
 community is up to date
 multilib is up to date
 archaudio-production is up to date
:: Starting full system upgrade...
[...]
Packages (60) [...]
Total Download Size:    47.35 MiB
Total Installed Size:  251.29 MiB
Net Upgrade Size:       -1.47 MiB

:: Proceed with installation? [Y/n]

Regards,
Ralf