title: V-REP's Lua `tonumber` returns nil on Linux
body: <p>We developed a simple <a href="http://www.coppeliarobotics.com/" rel="nofollow">V-REP</a> simulation that works pretty well on OS X but not on Linux (Ubuntu 15.04). <a href="http://www.lua.org/" rel="nofollow">Lua</a> is employed as the main scripting language.</p>
  
  <p>We attach the following code (with the return values in comments) that unfortunately returns <code>nil</code> on Linux (but converts <code>e[3]</code> to number without problem on OS X):</p>
  
  <pre><code>e[3]                   -- -0.677782532263
  type(e[3])             -- string
  type(tonumber(e[3]))   -- nil
  </code></pre>
  
  <p>What is really interesting is the fact that the previous code works as one would expect in Lua 5.2.3 console (both OS X and Linux). However, V-REP can't convert the string to number properly when running on Linux.</p>
  
  <p>We tried both <a href="http://www.coppeliarobotics.com/downloads.html" rel="nofollow">32b and 64b V-REP versions</a> (today downloaded) with exactly same results - <code>nil</code>s. Could you please point out some things we're missing? Neither Lua nor V-REP are utils we use every day.</p>
  
  <p><strong>Edit 1:</strong>
  I Use Ubuntu 15.04. V-REP uses Lua 5.1, My Lua version:</p>
  
  <pre><code>$ apt-cache policy lua5.1
  lua5.1:
    Installed: 5.1.5-7.1
    Candidate: 5.1.5-7.1
    Version table:
   *** 5.1.5-7.1 0
          500 http://cz.archive.ubuntu.com/ubuntu/ vivid/main amd64 Packages
          100 /var/lib/dpkg/status
  </code></pre>
  
  <p>In console, I tried the following:</p>
  
  <pre><code>$ lua
  Lua 5.1.5  Copyright (C) 1994-2012 Lua.org, PUC-Rio
  &gt; e={[3]="-0.677782532263"}; print(e[3], type(e[3]), tonumber(e[3]), type(tonumber(e[3])))
  -0.677782532263 string  -0.677782532263 number
  </code></pre>
  
  <p>Packages</p>