title: 'ccache' configuration
body: <p>I have a question related to ccache configuration. In our development environment we have hundreds of make files that build objects using absolute paths.</p>
  
  <p>I wanted to speed up the process and use ccache. Unfortunately when compiling from different locations I can see cache misses. Below is an example of
  simplified situation where source files are placed in different directories. How do I have to setup ccache to get the proper hit ratio?</p>
  
  <p>I tried to play with setting the CCACHE_BASEDIR variable with no success:</p>
  
  <pre><code>developer@crunchbang:~$ pwd
  /home/developer
  developer@crunchbang:~$ ccache -s
  cache directory                     /home/developer/.ccache
  cache hit (direct)                     0
  cache hit (preprocessed)               0
  cache miss                             0
  files in cache                         0
  cache size                             0 Kbytes
  max cache size                       1.0 Gbytes
  developer@crunchbang:~$ ccache g++ -c /home/developer/unique_name1/contest.cpp
  developer@crunchbang:~$ ccache g++ -c /home/developer/unique_name2/contest.cpp
  developer@crunchbang:~$ ccache -s
  cache directory                     /home/developer/.ccache
  cache hit (direct)                     0
  cache hit (preprocessed)               0
  cache miss                             2
  files in cache                         4
  cache size                            16 Kbytes
  max cache size                       1.0 Gbytes
  developer@crunchbang:~$ ccache g++ -c /home/developer/unique_name1/contest.cpp
  developer@crunchbang:~$ ccache g++ -c /home/developer/unique_name2/contest.cpp
  developer@crunchbang:~$ ccache -s
  cache directory                     /home/developer/.ccache
  cache hit (direct)                     2
  cache hit (preprocessed)               0
  cache miss                             2
  files in cache                         4
  cache size                            16 Kbytes
  max cache size                       1.0 Gbytes
  developer@crunchbang:~$ ccache --version
  ccache version 3.1.7
  
  Copyright (C) 2002-2007 Andrew Tridgell
  Copyright (C) 2009-2011 Joel Rosdahl
  
  This program is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free Software
  Foundation; either version 3 of the License, or (at your option) any later
  version.
  </code></pre>