From ripley at stats.ox.ac.uk  Thu Aug 12 17:32:11 2004
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Thu Aug 12 17:39:43 2004
Subject: [Rd] The Depends: field of a package is now used by library()
In-Reply-To: <85u0v89yae.fsf@servant.blindglobe.net>
Message-ID: <Pine.LNX.4.44.0408121627440.20697-100000@gannet.stats>

On Thu, 12 Aug 2004, A.J. Rossini wrote:

> Wolfgang Huber <w.huber@dkfz-heidelberg.de> writes:
> 
> >> On Thursday 12 August 2004 07:34, Prof Brian Ripley wrote:
> >>
> >>>In R-devel, the Depends: field in the DESCRIPTION file is now used by
> >>>library() to load the named packages before the current package, and
> >>>also to set up the environment to save images and prepare for lazy
> >>>loading.
> >>
> >
> > Are circular dependencies allowed?
> > Or do they need to be broken, e.g. by replacing one of the edges in a
> > loop by a "suggests"?
> 
> Argh -- BioC has something close to that for builds.  The release
> folks will have to explore that issue!

If all the packages were using saved images, nothing has changed, for the 
Depends: packages are the ones needed to save the image.  (The rest are 
Suggests:.)  And if a package is not using a saved image then the
Depends: are not needed to build it.

You can probably break this by building a package with --no-save and then 
building it later with --save.

-- 
Brian D. Ripley,                  ripley@stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595


[Rd] The Depends: field of a package is now used by library()
Prof Brian Ripley