Re: Profile support in apt

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

Hi,

On Tue, Jan 29, 2013 at 07:55:20AM +0800, Daniel Hartwig wrote:
> On 29 January 2013 01:47, Wookey <wookey@wookware.org> wrote:
> > If apt honours DEB_BUILD_PROFILE=foo then sbuild (which already has a
> > patch to set this) just sets it and everything should 'just work' (we
> > already have dpkg patches to make it DTRT).
> >
> > So, pointers as to which files/functions I should be looking at are
> > what this post hopes to elicit, although of course patches showing
> > just how trivial it is, would be even better :-)
> 
> Frontend: cmdline/apt-get.cc (DoBuildDeps).
> 
> Backend: apt-pkg/deb/debsrcparser.cc (BuildDepends),
> apt-pkg/deb/deblistparser.cc (ParseDepends).
> 
> Please check for the envvar in the frontend rather than the backend.

I hacked together a simple patch that just touches ParseDepends and
heavily borrows from the logic which parses architecture lists.

As wookey already pointed out it would be nice if apt could understand
the environment variable DEB_BUILD_PROFILE.  But the only environment
variable apt currently uses is APT_CONFIG.

So what would be the preferred way to read the variable in the frontend
and pass it to the backend? A new global variable? Or store it as part
of _config?  In that case a configuration variable APT::Profile could be
introduced, symmetric to APT::Architecture. But then again: no other
configuration currently has the option to be given by an environment
variable. Also, a profile is always selected on a per-package basis and
will never (and should never) be set globally.

So how would apt people like to have this done?

cheers, josch