Re: [PATCH] gnu: r: Update to 3.3.1.

[Pjotr Prins]

On Sat, Jul 30, 2016 at 03:41:50PM -0400, myglc2 wrote:
> The workaround used by sysops where I work (hospital research lab) is to
> give notice of R upgrades and to make previous releases available for
> reference by ongoing projects. IMO, we should consider how the guix R
> recipe(s) might support a pattern of use like this.
> 
> I can assure you that if our users do guix pull and invisibly get a new
> R release, their analyses will from time to time break. So we may want a
> simple way for them to back down to a previous release. So.. I am
> thinking it would make sense to keep previous versions of R in the
> recipe. What do others think?

Hi George,

If bioconductor tests pass on a new R build they *should* work. Guix
is not the same mess that Debian and Fedora are.

Note, meanwhile, that a new R install does not remove the old packages
automatically. One way to work older versions is by using guix
profiles effectively. We introduced Unix modules with Guix, so a
module would point to a well tested and working profile. Just make
sure it does not get GC'd at some point.

Another way to work it is by using a checked out Guix source tree.
That is what we do for Genenetwork deployment. Guix 'pull' simply
represents a version of the source tree - with its combination of
packages. You can force a combination of package versions by keeping
track of your own tree. See 

  https://github.com/genenetwork/genenetwork2/blob/master/doc/README.org

In the near future I hope we get a version of guix pull which can
essentially achieve the same (i.e. a checked out version of the tree).

  guix pull HASH-tag

Pj.