debug msg "holding back <pkg> rather than change <virtpkg>"

[Nick Cabatoff <ncc@cs.mcgill.ca>]

(I'm not subscribed to the list, please CC me any replies.)

I'm trying to determine why some package marked for installation
aren't being installed when I run apt-get dselect-upgrade.  My C++
isn't so hot these days, so I would appreciate any help.  My
understanding is that if A depends on B | C, and B is a real package,
apt-get shouldn't have a problem with it.  I don't think I should have
to specify B as 'install' to dpkg --set-selections if it is a
dependancy of A and A *is* flagged as 'install'.  Here's an example:

Running with the pkgproblemresolver on, I get
messages for the packages in question of the form of

  Package at has broken dep on localcfg-at-base
    Considering localcfg-at-base 1 as a solution to at 3
    Holding Back at rather than change localcfg-at-base

dpkg --get-selections returns the following line for the packages in
question:

  at                                              install

apt-cache showpkg at localcfg-at localcfg-at-base returns:
(reformated slightly for readability)

  Package: at
  Versions: 5:3.1.8-4(/var/state/apt/lists/slink_aptupdate_Packages),
  3.1.8-4(/var/lib/dpkg/status),
  Reverse Depends:
    localcfg-at-base,at
  Dependencies:
  5:3.1.8-4 - libc6 (2 2.0.7u) mail-transport-agent (16 (null)) 
  smail (16 (null)) mailx (0 (null)) localcfg-at-base (16 (null)) 
  localcfg-at (0 (null)) 3.1.8-4 - libc6 (2 2.0.7u) 
  mail-transport-agent (16 (null)) smail (16 (null)) mailx (0 (null)) 
  Provides: 
  5:3.1.8-4 - 
  3.1.8-4 - 
  Reverse Provides: 
  
  Package: localcfg-at
  Versions:
  Reverse Depends:
    at,localcfg-at
  Dependencies:
  Provides:
  Reverse Provides:
  localcfg-at-base 3.1.8-4-0
  
  Package: localcfg-at-base
  Versions: 3.1.8-4-0(/var/state/apt/lists/slink_aptupdate_Packages)
  (/var/state/apt/lists/slink_cfgpackages_Packages),
  Reverse Depends:
    at,localcfg-at-base
  Dependencies:
  3.1.8-4-0 - at (0 (null))
  Provides:
  3.1.8-4-0 - localcfg-at
  Reverse Provides:
  
This is with apt 0.3.19 running on a slink-based system.