Re: [gentoo-user] What's with foomatic-filters and cups-filters?

[Alan Mackenzie <acm@muc.de>]

Good morning, Andreas!

On Sun, Jun 08, 2014 at 07:15:36PM +0200, Andreas K. Huettel wrote:
> Am Sonntag, 8. Juni 2014, 17:48:09 schrieb Alan Mackenzie:
> > .   What is all this trying to tell me?  I've tried for over an hour to
> > make sense of it, but my eyes just glaze over.  My best guess is that
> > cups-filters and foomatic-filters are packages which can't be installed
> > together.  But I _need_ foomatic-filters - otherwise my printer doesn't
> > print.  Or do I?  cups-filters seems to be needed by cups.

> > What _are_ cups-filters and foomatic-filters?  emerge -s is little help
> > here.  Why do I need both of them?

> * cups-filters is a former part of cups that provides file format conversions 
> (among other things). Basically it (also) makes sure that everything is 
> internally converted to PDF. It's not part of CUPS (as maintained by Apple) 
> anymore, but hard-required by CUPS on Linux (and maintained by the Linux 
> Foundation). 

> * foomatic-filters is a set of printer drivers, basically. 

> * Some time ago the cups-filters maintainers took over maintainership of the 
> foomatic-filters part for CUPS as well, and integrated it cleanly into cups-
> filters. That's the reason for the blocker; recent cups-filters contain the 
> newest foomatic code available. The former separate foomatic-filters package 
> is now unmaintained.

Thanks!  That was brilliantly clear and informative.

> So, we have the following possibilities for installation: 

> 1) normal CUPS user, recommended, this is what comes by default (unless you do 
> something stupid such as USE="-*")
> net-print/cups
> net-print/cups-filters[foomatic]

This is what I now have.

> 2) NOT recommended, dead code, unmaintained: 
> net-print/cups
> net-print/cups-filters[-foomatic]
> net-print/foomatic-filters

> 3) for the stone age people out there, NOT recommended, dead code, 
> unmaintained:
> any other printing system, e.g. lprng
> net-print/foomatic-filters

I had lprng when I first installed Gentoo (2010).  It just worked (with
apsfilter(?s) rather than foomatic).  Was forced, with regret, to switch
to cups when libreoffice stopped supporting traditional print spoolers.

> So, what's wrong in your case? No idea, but after longish not-updating things 
> do get hard for emerge to unravel. My recommendation is, since foomatic-
> filters and cups-filters are only needed for printing and emerge runs fine 
> without them, force-remove both and let emerge figure out the right package 
> set from scratch.  

This worked!  I now have printing.

> [This basically works with any blocker as a last resort, but can be *very* 
> dangerous for packages that are needed by the core system. You definitely 
> don't want to remove gcc or glibc this way, for example. :)]

> emerge -aC net-print/cups-filters net-print/foomatic-filters
> emerge -uDNavt --backtrack=100 world

I've not plucked up the courage for the world emerge, yet.

But the original bug was that I had to get --debug output from emerge to
see that it was the foomatic/cups stuff that was clashing.  This wasn't
contained in the normal, somewhat obscure, emerge error messages.

> Cheers, 
> Andreas

> -- 
> Andreas K. Huettel
> Gentoo Linux developer (council, kde)
> dilfridge@gentoo.org
> http://www.akhuettel.de/

-- 
Alan Mackenzie (Nuremberg, Germany).