[gentoo-dev] Re: Dependencies on system packages

[Ryan Hill]

Alec Warner <antarus@g.o> wrote:

> Hrm, I thought I wrote about this a while ago but I don't see it on
> archives.g.o so lets try again.
>
>  > If your package is 'not important' meaning it will never be in
>  > 'system' for any profile, you should not depend on anything in
>  > 'system', as
> stuff in system should already be installed in a given (sane)
> configuration.
>  >
>  > If your package may be in 'system' in a given profile, you need to
> ensure your package builds in the proper order, with regards to other
> system packages.  The classic example is zlib; if you need zlib to
> uncompress something, then you should put zlib in the deps; that way
> when someone is building say, a stage1, your package will build after
> zlib, instead of before it.
>  >
>  > You have to be careful in deciding what to specify, as doing
>  > things
> incorrectly in this case can often cause dependency loops which are
> sometimes fun to debug; perl and openssl were infamous back in the
> day for this.
>  >
>  > Enterprising users would specify the 'doc' useflag. openssl
>  > requires
> perl to generate its docs and perl requires openssl for some
> encryption stuff.  Users would then complain about perl or openssl
> not building, or portage getting really pissed at them; the solution
> being to build openssl twice, once with USE="-doc" and then build
> perl, and then rebuild openssl with USE="doc".  This certainly wasn't
> the only case where this occurred (see ML thread about shadow and
> it's dep on some other package I can't remember, although that was a
> while back as well).
>  >
>  > In conclusion, you need domain knowledge of system packages and
> portage behavior to make good choices here ;)
>
> Wow that pasted nastily; hopefully it shows up ok ;)
>
> In any case I'm sure there are some other exceptions but these are
> the main ones.

Cool, that's exactly what I was looking for.

thanks ;d