Issue with dependency and packages availability

[Mick Bert <MickBert@posteo.net>]

Hello

Today I'm taking my ibookG4 out of his box, with the aim of a simple 
daily use (I' currently writing with Thunderbird running on it). I had 
some issues installing the wireless related packages, and I thought it 
was an isolated case, but I found similar issue installing emacs, so I 
wonder if there are something in my apt configuration which I should 
check. The issue is, as example:

The following packages have unmet dependencies:
 emacs : Depends: emacs-gtk (>= 1:27.1) but it is not installable or
                  emacs-lucid (>= 1:27.1) but it is not installable or
                  emacs-nox (>= 1:27.1) but it is not installable
E: Unable to correct problems, you have held broken packages.

Than with "apt-get install emacs-lucid":

The following packages have unmet dependencies:
 emacs-lucid : Depends: emacs-bin-common (= 1:27.1+1-3) but it is not 
going to be installed
               Depends: emacs-common (= 1:27.1+1-3) but it is not going 
to be installed
E: Unable to correct problems, you have held broken packages.

The firs time I noticed it was installing firmware-b43-installer, which 
required b43-fwcutter which is not available. I resolve downloading and 
installing an old version of such packages.

Any hint?

--

Mick