title: CSV.open(..) block does not execute, and ends immediately
body: <p>I am opening a CSV file for writing with the following code, as indicated in CSV documentation here (http://ruby-doc.org/stdlib-1.9.2/libdoc/csv/rdoc/CSV.html):</p>
  
  <pre><code>CSV.open( csv_file_out, 'wb' ) { |csv_line_out|
  
    #stuff happens here
  
  }
  </code></pre>
  
  <p>the block does not execute, i.e. after the CSV.open command debugger goes directly to the end of block. </p>
  
  <p>thinking "just in case", I try the same with IO modes <code>w+b</code> <code>wt</code> <code>w+t</code> <code>ab</code> <code>a+b</code>. I also tried creating the file before the in case there was a problem with opening it. nothing changes. </p>
  
  <p>when I stop the debugger at the <code>CSV.open</code> line, I am able to execute a block manually and create a csv file myself. I can also create the file frmo the exact same command from console. But it won't work when executed in the server. </p>
  
  <p>Any ideas on what's going on are very welcome. Thanks in advance!</p>