Comment 3 for bug 441059

Daniel Hartwig (wigs) wrote :

> speaking in more general terms, aptitude generally fails to accept "keep
> everything as it is" when there are currently no unresolved conflicts but
> updates introduce irreconcilable conflicts. Aptitude will not present "hold
> all packages" as a solution.

You may find adding this to /etc/apt/apt.conf relieves the issue:
 Aptitude::ProblemResolver::Discard-Null-Solution "false";