title: problems installing packages on server after update to 2.15
body: <p>I have a recurring problem installing packages, that often looks like this:</p>
  
  <pre><code>&gt; install.packages("Biobase")
  Installing package(s) into ‘/usr/local/lib/R/site-library’
  (as ‘lib’ is unspecified)
  Warning in install.packages("Biobase") :
    'lib = "/usr/local/lib/R/site-library"' is not writable
  Would you like to create a personal library
  ~/R/x86_64-pc-linux-gnu-library/2.15
  to install packages into?  (y/n) y
  --- Please select a CRAN mirror for use in this session ---
  Loading Tcl/Tk interface ... done
  Warning message:
  package ‘Biobase’ is not available (for R version 2.15.0) 
  </code></pre>
  
  <p>My <code>Sys.info()</code> is as follows:</p>
  
  <pre><code>&gt; Sys.info()
                                       sysname 
                                       "Linux" 
                                       release 
                            "2.6.32-40-server" 
                                       version 
  "#87-Ubuntu SMP Tue Mar 6 02:10:02 UTC 2012" 
                                      nodename 
                                      "******" 
                                       machine 
                                      "x86_64" 
                                         login 
                                          "**" 
                                          user 
                                          "**" 
                                effective_user 
                                          "**" 
  </code></pre>
  
  <p>Is the error <code>package ‘Biobase’ is not available (for R version 2.15.0)</code> due to the fact that I have to install it in a personal library (apparently on the server I work on, the usual library is not writable)? How can I get around this, as I seem to get the same "not available for 2.15" error anytime I try to install a package.</p>