Log Message:
ccache: updated to 3.7.9

ccache 3.7.9

Bug fixes
Fixed replacing of /dev/null when building as root with hard link mode enabled \ 
and using -o /dev/null.
Removed incorrect assertion resulting in “ccache: error: Internal error in \ 
format” when using -fdebug-prefix-map=X= with X equal to $PWD.

Other
Improved CUDA/NVCC support: Recognize -dc and -x cu options.
Improved name of temporary file used in NFS-safe unlink.