2016-06-27 18:10, Wiles, Keith:

It appears the ccache and clang have a few problems without the global having the environment variable set:
export CCACHE_CPP2=yes

Without this environment variable clang starts to complain about a number of issues. If you see a compile problem please rebuild with ccache disabled using ‘sudo CCACHE_DISABLE=true …’ or uninstall ccache ‘sudo apt-get remove ccache’

With ccache 3.2, it is possible to replace the environment variable
CCACHE_CPP2=yes by the configuration run_second_cpp=true in ccache.conf.

See http://peter.eisentraut.org/blog/2014/12/01/ccache-and-clang-part-3/

It is possible that GCC will also have compiler issues, but I do not seem to see any, just try without ccache to verify.

Here is a link to help explain more details:
See e.g. http://petereisentraut.blogspot.com/2011/09/ccache-and-clang-part-2.html

If the build works then I have not found any issues with using ccache except a faster build time ☺  YMMV 

Regards,
Keith