title: Failed to "rbt post <CHANGENUM>" from Perforce P4V
body: <p>I'm trying to "rbt post CHANGENUM"(CHANGENUM is the number of pending list) from Perforce P4V in Windows7.
  I succeeded to execute this command from command prompt, but I failed to execute from Perforce P4V with the error below.</p>
  
  <pre><code>&gt;&gt;&gt; RBTools 0.7.1 alpha 0 (dev)
  &gt;&gt;&gt; Python 2.7.6 (default, Nov 10 2013, 19:24:18) [MSC v.1500 32 bit (Intel)]
  
  &gt;&gt;&gt; Running on Windows-7-6.1.7601-SP1
  &gt;&gt;&gt; Home = C:\Users\xxxx\AppData\Roaming
  &gt;&gt;&gt; Current directory = c:\Users\xxxx\p4vworkspace
  
  &gt;&gt;&gt; Checking for a Subversion repository...
  &gt;&gt;&gt; Unable to execute "svn help": skipping SVN
  &gt;&gt;&gt; Checking for a Git repository...
  &gt;&gt;&gt; Running: git rev-parse --git-dir
  
  &gt;&gt;&gt; Command exited with rc 128: ['git', 'rev-parse', '--git-dir']
  fatal: Not a git repository (or any of the parent directories): .git
  ---
  &gt;&gt;&gt; Checking for a Mercurial repository...
  
  &gt;&gt;&gt; Unable to execute "hg --help": skipping Mercurial
  &gt;&gt;&gt; Checking for a CVS repository...
  &gt;&gt;&gt; Unable to execute "cvs": skipping CVS
  &gt;&gt;&gt; Checking for a Perforce repository...
  &gt;&gt;&gt; Running: p4 info
  
  &gt;&gt;&gt; Running: diff --version
  
  &gt;&gt;&gt; repository info: Path: perforce.tw.trendnet.org:1666, Base path: None, Supports changesets: True
  &gt;&gt;&gt; Making HTTP GET request to http://xxxxx/api/
  
  Path 'CHANGENUM' does not match a valid Perforce path.
  </code></pre>
  
  <p>CustomTool settings are below</p>
  
  <p>■ Application:C:\Program Files\RBTools\bin\rbt.cmd</p>
  
  <p>■ Arguments: post -d %p</p>
  
  <p>Do you have any ideas to fix it ?</p>