dpkg --print-avail PACKAGE fails

Question

I just happened to notice that dpkg --print-avail PACKAGE (same as dpkg -p PACKAGE) is failing on my Ubuntu 10.04.2 server. Should I be concerned?

For example:

$ dpkg -p a2ps
Package `a2ps' is not available.

But:

$ dpkg -l a2ps
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Inst/Cfg-files/Unpacked/Failed-cfg/Half-inst/trig-aWait/Trig-pend
|/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
||/ Name            Version         Description
+++-===============-===============-==============================================
ii  a2ps            1:4.14-1        GNU a2ps - 'Anything to PostScript' converter

Also, apt-cache show a2ps, recommended in the dpkg manual for "Users of APT-based frontends" (like me), does work.

Based on these bugs, I'm guessing it doesn't matter that dpkg -p PACKAGE fails:

• http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=43573
• http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=137128

Answer 1

No need to be concerned at all. dpkg only looks to see if packages are available in /var/lib/dpkg/available From the manpage:

          -p, --print-avail package-name...
              Display details about package-name, as found in
              /var/lib/dpkg/available. Users of APT-based frontends
              should use apt-cache show package-name instead. 

Where apt-cache policy PACKAGE also checks your apt sources.