title: Setting proxy on .Rprofile on OSX fails
body: <p>In order to access CRAN packages from within R on OSX I've been using</p>
  
  <pre><code>Sys.setenv(http_proxy="http://blah_blah:1234/")
  </code></pre>
  
  <p>as the first command in the R GUI for a while, but would really like to set this proxy automatically.</p>
  
  <p>I've tried unsuccessfully to get the same command to work in a .Rprofile file in ~/</p>
  
  <p>I've also tried <code>http_proxy="http://blah_blah:1234/"</code>, but this fails too.</p>
  
  <p>The error I get when I try to view packages is a drop-down window that says:</p>
  
  <pre><code>Fetching Package List Failed
  Please consult R Console output for details
  </code></pre>
  
  <p>The GUI then gives:</p>
  
  <pre><code>Error in read.dcf(file = tmpf) : Line starting '&lt;head&gt; ...' is malformed!
  </code></pre>
  
  <p>The .Rprofile file itself seems to be loading (checked using <code>cat("my profile works\n"))</code></p>