git --no-pager diff 105fca2b42051c5cd0894da31839c99a9b7de320:debian/r-base 56cb59cc262e9d2c02f9e11cfacab65f0b659c5f:r-base

r-base.diff

diff --git a/Dockerfile b/Dockerfile
index fc67592..ff25f25 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,45 +7,48 @@ MAINTAINER "Carl Boettiger and Dirk Eddelbuettel" rocker-maintainers@eddelbuette
 
 ## Set a default user. Available via runtime flag `--user docker` 
 ## Add user to 'staff' group, granting them write privileges to /usr/local/lib/R/site.library
-## User should also have & own a home directory (for rstudio or linked volumes to work properly). (could use adduser to create this automatically instead)
+## User should also have & own a home directory (for rstudio or linked volumes to work properly). 
 RUN useradd docker \
-&& mkdir /home/docker \
-&& chown docker:docker /home/docker \
-&& addgroup docker staff
+  && mkdir /home/docker \
+  && chown docker:docker /home/docker \
+  && addgroup docker staff
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN apt-get update \ 
+  && apt-get install -y --no-install-recommends \
     ed \
     less \
     locales \
     vim-tiny \
-    wget
+    wget \
+  && rm -rf /var/lib/apt/lists/*
 
 ## Configure default locale, see https://github.com/rocker-org/rocker/issues/19
 RUN echo "en_US.UTF-8 UTF-8" >> /etc/locale.gen \
-&& locale-gen en_US.utf8 \
-&& /usr/sbin/update-locale LANG=en_US.UTF-8
+  && locale-gen en_US.utf8 \
+  && /usr/sbin/update-locale LANG=en_US.UTF-8
+
 ENV LC_ALL en_US.UTF-8
 
-## Use Debian repo at CRAN, and use RStudio CDN as mirror
-## This gets us updated r-base, r-base-dev, r-recommended and littler
-RUN apt-key adv --keyserver keys.gnupg.net --recv-key 381BA480 \
-&& echo "deb http://cran.rstudio.com/bin/linux/debian wheezy-cran3/" > /etc/apt/sources.list.d/r-cran.list
+## Use Debian unstable via pinning (see apt-preferences.txt)
+RUN echo "deb http://http.debian.net/debian sid main" > /etc/apt/sources.list.d/debian-unstable.list
+COPY apt-preferences.txt /etc/apt/preferences.d/apt-pinning.pref
 
 ENV R_BASE_VERSION 3.1.2
 
 ## Now install R and littler, and create a link for littler in /usr/local/bin
-RUN apt-get update -qq \
-&&  apt-get install -y --no-install-recommends \
-    littler \
+RUN apt-get update \
+  && apt-get install -t unstable -y --no-install-recommends \
+    littler/unstable \
     r-base=${R_BASE_VERSION}* \
     r-base-dev=${R_BASE_VERSION}* \
     r-recommended=${R_BASE_VERSION}* \
-&&  ln -s /usr/share/doc/littler/examples/install.r /usr/local/bin/install.r \
-&&  ln -s /usr/share/doc/littler/examples/install2.r /usr/local/bin/install2.r \
-&&  ln -s /usr/share/doc/littler/examples/installGithub.r /usr/local/bin/installGithub.r \
-&&  ln -s /usr/share/doc/littler/examples/testInstalled.r /usr/local/bin/testInstalled.r \
-&&  install.r docopt \
-&&  rm -rf /tmp/downloaded_packages/ /tmp/*.rds
+  && ln -s /usr/share/doc/littler/examples/install.r /usr/local/bin/install.r \
+  && ln -s /usr/share/doc/littler/examples/install2.r /usr/local/bin/install2.r \
+  && ln -s /usr/share/doc/littler/examples/installGithub.r /usr/local/bin/installGithub.r \
+  && ln -s /usr/share/doc/littler/examples/testInstalled.r /usr/local/bin/testInstalled.r \
+  && install.r docopt \
+  && rm -rf /tmp/downloaded_packages/ /tmp/*.rds \
+  && rm -rf /var/lib/apt/lists/*
 
 ## Set a default CRAN Repo
 RUN echo 'options(repos = list(CRAN = "http://cran.rstudio.com/"))' >> /etc/R/Rprofile.site
diff --git a/apt-preferences.txt b/apt-preferences.txt
new file mode 100644
index 0000000..427654c
--- /dev/null
+++ b/apt-preferences.txt
@@ -0,0 +1,18 @@
+
+## This is straight from Jacque's old HOWTO at
+##     http://jaqque.sbih.org/kplug/apt-pinning.html
+## 
+## Dirk Eddelbuettel, 19 Jan 2015
+
+Package: *
+Pin: release a=stable
+Pin-Priority: 700
+
+Package: *
+Pin: release a=testing
+Pin-Priority: 650
+
+Package: *
+Pin: release a=unstable
+Pin-Priority: 600
+