Bug#526661: [aptitude]

[Daniel Burrows <dburrows@debian.org>]

  *bangs head on desk*

  So here's what we have.  aptitude tries to avoid downloading a new
copy of a changelog by instead reusing one that it finds installed on
the system.  To do this, it looks up the source package and checks
whether any of its binaries are installed, which requires reading in
apt's list of source records.  You don't have any source records, so
the source record of the package can't be found, so aptitude won't try
to use a locally installed changelog (maybe instead it should check for
a changelog from the same binary, but it won't).

  Here's the wall-banger: the apt object representing the list of source
records emits the error message you're seeing *in its constructor* if
you don't have any source records listed in /etc/apt/sources.list.  Even
more fun, I don't see any reasonable way (short of duplicating a bunch
of apt code) to replicate the test it uses exactly.  I'll implement a
quick and dirty workaround, but this is really an apt bug IMO.

  Daniel