title: Can't install perl with perlbrew
body: <p>I encountered the error when install perl-5.14.2 with perlbrew.</p>
  
  <p>On Ubuntu11.10(64-bit), I try</p>
  
  <pre><code>$ perlbrew install perl-5.14.2 -Dperlibs='-lm -lc' -Dusethreads -Dplibpth=/usr/lib/x86_64-linux-gnu
  </code></pre>
  
  <p>and got the error</p>
  
  <pre><code>IO.xs: In function ‘XS_IO__Poll__poll’:
  IO.xs:249:17: error: invalid application of ‘sizeof’ to incomplete type ‘struct pollfd’
  </code></pre>
  
  <p>How can i solve this error?</p>