Re: possible MBF: automatically detecting unused build dependencies

[Johannes Schauer <j.schauer@email.de>]

Hi,

Quoting Kurt Roeckx (2014-07-09 00:36:37)
> On Mon, Jul 07, 2014 at 01:51:00PM +0200, Johannes Schauer wrote:
> > Kurt Roeckx <kurt@roeckx.be>
> >    libtool
> 
> ==> libtool_2.4.2-1.7.arch-all.unusedbd <==
> gfortran=4:4.8.2-4
> 
> gfortran Depends on gfortran-4.8, and that is being used.

indeed this is then a false positive of a nearly-meta package. Unfortunately
the gfortran package does ship some files besides /usr/share/doc (both
symlinks) and would thus not be classified as a meta package.

Maybe I should also check debtags. gfortran is tagged role::dummy. I also found
role::metapackage. Is there another debtag or method in general that would
allow to consider the dependencies of a package instead and avoid this kind of
false positive?

Maybe a package shipping only symlinks besides /usr/share/doc is another way of
finding meta packages. On the other hand it's harder to check the type of file
a package ships as it needs downloading and unpacking first. I'm not aware
whether tools like apt-file display information about the file type.

> 
> >    openssl (U)
> ==> openssl_1.0.1g-4.arch-all.unusedbd <==
> m4=1.4.17-4
> 
> >From the changelog:
>   * Add Build-Dependency on m4, since sparc needs it to generate
>     it's assembler files.  (Closes: #334542)

Then it makes sense that my amd64 build caught that. Could you make m4 an
architecture specific dependency if it's only used on sparc?

cheers, josch