NixOS/nixpkgs — pull request #3208 by jbedo (2014-07-08 01:10:51+00:00)
Title: Fix R expressions when packages are updated

The CRAN archive has a directory structure that shifts the location of tarballs when a new version is released. Currently the R package derivation does not check the archive for tarballs and consequently whenever a CRAN package is updated all the dependent build expressions break. This patch adds the archive to the list of sources so older versions can be found, and removes a problematic mirror.