title: How to adjust future.global.maxSize?
body: <p>Here's a useless example that shows my point</p>
  <pre class="lang-r prettyprint-override"><code>library(future)
  a = 1:200000000
  object.size(a)
  test %&lt;-% head(a)
  </code></pre>
  <p>I get the following error:</p>
  <blockquote>
  <p>Error in getGlobalsAndPackages(expr, envir = envir, persistent =
  persistent,  : The total size of all global objects that need to be
  exported for the future expression (‘head(a)’) is 762.95 MiB. This
  exceeds the maximum allowed size of 500.00 MiB (option
  'future.global.maxSize'). There are two globals:  ‘a’ (762.94 MiB of
  class ‘numeric’) and ‘head’ (10.05 KiB of class ‘function’).</p>
  </blockquote>
  <p>Can anyone help me understand how to adjust that future.global.maxSize option? I tried <code>options(future.global.maxSize = 1500000)</code> but that didn't work.</p>