From Fedora Project Wiki

Ccache Plugin

The ccache plugin is a compiler cache plugin. It is enabled by default and has an upper limit of 4GB of ccache data.


Configuration

The ccache plugin is enabled by default and has the following values built-in:

   config_opts['plugin_conf']['ccache_enable'] = True
   config_opts['plugin_conf']['ccache_opts']['max_cache_size'] = '4G'
   config_opts['plugin_conf']['ccache_opts']['compress'] = None
   config_opts['plugin_conf']['ccache_opts']['dir'] = "%(cache_topdir)s/%(root)s/ccache/u%(chrootuid)s/"

To turn on ccache compression, use the following in a config file:

   config_opts['plugin_conf']['ccache_opts']['compress'] = 'on'

The value specified is not important, this just triggers the setting of the CCACHE_COMPRESS environment variable, which is what the ccache program uses to determine if compression of cache elements is desired.