The SystemRequirements field on the DESCRIPTION file is used to document the system requirements. For example, the DESCRIPTION file for Ryacas (which requires yacas) is shown below.
Package: Ryacas Version: 0.2-8 Date: 2007-08-22 Title: R interface to the yacas computer algebra system Author: Rob Goedman <[EMAIL PROTECTED]>, Gabor Grothendieck <[EMAIL PROTECTED]>, Søren Højsgaard <[EMAIL PROTECTED]>, Ayal Pinkus <[EMAIL PROTECTED]> Maintainer: G Grothendieck <[EMAIL PROTECTED]> Encoding: latin1 Description: An interface to the yacas computer algebra system. Depends: R (>= 2.5.1), XML SystemRequirements: yacas (>= 1.0.63) # instructions on home page License: GPL URL: http://ryacas.googlecode.com On Nov 22, 2007 10:58 AM, Neil Shephard <[EMAIL PROTECTED]> wrote: > Hi, > > I noticed recently when installing the GDD package for R under > GNU/Linux that it required the gd library (http://libgd.org/) for > generating graphics. > > The resolution of this was to simply install the library on my system, > and then GDD successfully installed without any complaints. > > However, the variant of GNU/Linux that I use is Gentoo, so I filed a > bug requesting that a USE flag be set for the R ebuild so that users > could automatically pull in the library when installing R simply by > setting a flag for the package (Gentoo's package management system > Portage allows specific packages to have USE flags for setting a packages > ./configure flags and pulling in package dependencies and so forth, > this isn't particularly relevant to the question, but more info can be > found at http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=3). > A recent revision of the ebuild for R removed this flag as there was > no direct requirement of the gd library by R. > > Anyway, after a few short discussions with one of the Gentoo > maintainers for R I was asked various questions about how this should > be dealt with, and being unable to answer everything I am asking the > wider R community for assistance and advice. The main aim is to > improve the way in which Gentoo handles the various packages that are > available for R, and improve on the way in which dependencies such as > the above are handle when compiling R. > > Q.1 How many packages on CRAN have package specific dependencies? > > Only using a subset of the R packages I'm only aware of the GDD > dependency on libgd. Are there others out there? > > Q.2. Is R capable of tracking dependencies of packages on CRAN? > > To my knowledge it isn't, as (to the best of memory, it was about six > months ago now) I simply received a non-zero exit when trying to > install GDD when I didn't have libgd installed. R had no way of > saying "Hang on this package needs this library, lets install it" and > I wouldn't expect R to as it would make it particularly problematic if > a user has installed locally or doesn't have the correct permissions etc. But > would it be appropriate for R to have a configure option to check for > a dependency required by various packages? I do realise that this is > putting the cart before the horse. Perhaps 'stricter' management of > package inclusion would help so that all dependencies of a submitted > package are passed onto R developers and appropriate configure flags > can be added (although again this still leaves the horse behind the > cart). > > > Q.3. Does anyone have experience of dealing with this on other distributions? > > How does Debian/Slackware/Fedora etc. deal with problems like this? > Particularly given that these are often pre-compiled (under Gentoo > everything is compiled from source), does this mean that package > maintainers of R for these various distros are aware of the > dependencies of all packages and include the relevant libraries when > compiling? > > The Gentoo R maintainer is going to look at alternatives for managing > CRAN packages (one possible option is http://paludis.pioto.org/ which > has some CRAN support already). > Something similar has been done for Perl/CPAN (see > http://www.gentoo.org/proj/en/perl/g-cpan.xml) and this may be an > option for CRAN. > > Any and all comments and thoughts are more than welcome. > > Regards > > Neil > -- > "Don't remember what you can infer." - Harry Tennant > > Email - [EMAIL PROTECTED] / [EMAIL PROTECTED] > Website - http://slack.ser.man.ac.uk/ > Photos - http://www.flickr.com/photos/slackline/ > > > > -- > "Don't remember what you can infer." - Harry Tennant > > Email - [EMAIL PROTECTED] / [EMAIL PROTECTED] > Website - http://slack.ser.man.ac.uk/ > Photos - http://www.flickr.com/photos/slackline/ > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
