[R-sig-Debian] Picking 'rgl' as source package instead of 'r-cran-rgl'

[Matt Dowle]

Hi,

$ more /etc/apt/sources.list.d/additional-repositories.list
deb http://www.stats.bris.ac.uk/R/bin/linux/debian wheezy-cran3/
deb-src http://www.stats.bris.ac.uk/R/bin/linux/debian wheezy-cran3/

$ sudo apt-get update

$ sudo apt-get install r-cran-rgl      # works great

$ sudo apt-get build-dep r-cran-rgl
Reading package lists... Done
Building dependency tree
Reading state information... Done
Picking 'rgl' as source package instead of 'r-cran-rgl'
E: Unable to find a source package for rgl

What have I done wrong?!

Thanks, Matt