From b.rowlingson at lancaster.ac.uk  Thu Dec 13 00:05:20 2012
From: b.rowlingson at lancaster.ac.uk (Barry Rowlingson)
Date: Wed, 12 Dec 2012 23:05:20 +0000
Subject: [Rd] =?windows-1252?q?SystemRequirements=92_field?=
In-Reply-To: <47ce74456609465db2defc7d092c681f@EX-0-HT0.lancs.local>
References: <50C8CDF5.3020401@gmail.com> <50C8D8AA.7010701@stats.ox.ac.uk>
	<47ce74456609465db2defc7d092c681f@EX-0-HT0.lancs.local>
Message-ID: <CANVKczPo_Es28rN9JH+4EHqgnnrDyHfkkC0_JYbgqcLAr1Zx_Q@mail.gmail.com>

I see three references to systemRequirements in Writing R Extensions.
The one you list in your last email, this one:

"If your package requires one of these interpreters or an extension
then this should be declared in the ?SystemRequirements? field of its
DESCRIPTION file." [for listing interpreters to run scripts]

and

"If you really must assume GNU make, declare it in the DESCRIPTON file by

          SystemRequirements: GNU make"

A grep of a complete R 2.15-2 source tree doesn't show it being used
either. It's mentioned in the OONEWS file for R 1.7.0

"It is now recommended to use the 'SystemRequirements:' field in the
DESCRIPTION file for specifying dependencies external to the R
system."

Grepping all the DESCRIPTION files on my work box shows such values
for that field as:

"GRASS (>=6.3)"
"An ODBC3 driver manager and drivers"
"libxml2 (>=2.6.3)"
"OpenGL, GLU Library, zlib (optional), libpng)
"for building from source: GDAL >= 1.6.0 library"

some of which look pretty free-form descriptive to me.

Hope that's a bit more useful than 'No'.

On Wed, Dec 12, 2012 at 7:55 PM, Paul Gilbert <pgilbert902 at gmail.com> wrote:
>
>
> On 12-12-12 02:19 PM, Prof Brian Ripley wrote:
>> On 12/12/2012 18:33, Paul Gilbert wrote:
>>> Am I correct in thinking that the ?SystemRequirements? field in a
>>> package DESCRIPTION file is purely descriptive, there are no standard
>>> elements that can be extracted by parsing it and used automatically?
>>
>> No.
>>
>
> Where can I find more details?  The section "The DESCRIPTION file" in
> "Writing R Extensions" says only:
>
>     Other dependencies (external to the R system) should be listed in
>     the ?SystemRequirements? field, possibly amplified in a separate
>     README file.
>
> Thanks,
> Paul
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel



[Rd] =?windows-1252?q?SystemRequirements=92_field?=
Barry Rowlingson