How to get rid of tex-common with an equivs built texlive-dummy?

[sktsee]

On Sun, 14 Feb 2010 12:47:56 +0100, Christoph Bier wrote:

> Hi,
> 
> in order to install LyX without installing Ubuntu's TeXLive 2007 I built
> a texlive-dummy package with equivs. The texlive.ctl has the following
> content in "Provides":
> 
> dvipdfmx, dvipng, lacheck, latex-beamer, latex-xcolor, pgf,
> preview-latex-style, psutils, tex-common, texlive-base,
> texlive-base-bin, texlive-base-bin-doc, texlive-common,
> texlive-doc-base, texlive-extra-utils, texlive-fonts-recommended,
> texlive-fonts-recommended-doc, texlive-generic-extra,
> texlive-generic-recommended, texlive-humanities, texlive-humanities-doc,
> texlive-latex-base, texlive-latex-base-doc, texlive-latex-extra,
> texlive-latex-extra-doc, texlive-latex-recommended,
> texlive-latex-recommended-doc, texlive-pictures, texlive-pictures-doc,
> texlive-pstricks, texlive-pstricks-doc, tipa
> 
> As you can see it contains tex-common. But after the installation of
> texlive-dummy APT still wants to install tex-common when asked to
> install LyX. What did I miss?
> 
> Best
> Christoph

Not real familiar with equivs, but it looks to me as if you are running 
into this bit from the Debian Policy Manual
http://www.debian.org/doc/debian-policy/ch-relationships.html

>From Section 7.5 Virtual packages - Provides
...
"If a relationship field has a version number attached then only real 
packages will be considered to see whether the relationship is satisfied 
(or the prohibition violated, for a conflict or breakage) - it is assumed 
that a real package which provides the virtual package is not of the 
"right" version. So, a Provides field may not contain version numbers, 
and the version number of the concrete package which provides a 
particular virtual package will not be looked at when considering a 
dependency on or conflict with the virtual package name. "

One Lyx's dependencies is lyx-common, which has this dependeny:
$ apt-cache show lyx-common |grep Depend
Depends: dpkg (>= 1.14.18), tex-common (>= 1.18), python, python-support 
(>= 0.90.0)

lyx-common specifically depends on a version of tex-common >=1.18. 
According to the policy stated above, when dpkg sorts out the 
dependencies, it's going to prefer a "real" package over a virtual one if 
a dependency lists a specific version number. 

I guess one way to solve this problem would be to create and install a 
dummy tex-common package. I assume that's possible to do with the equivs 
program, though I'm unsure on the specific steps to accomplish it.

-- 
sktsee