RunCMake.SymlinkTrees failure because of CCACHE_BASEDIR
Install `ccache` and use `ccache` to build cmake with:
```
cd /path/to/cmake/source &&
export CCACHE_BASEDIR="$PWD" &&
mkdir bbb &&
cmake -GNinja .. &&
ninja &&
ctest -R RunCMake.SymlinkTrees
```
[st.log](/uploads/b82e6856f2d76a62ab45a2e8e7a9b664/st.log)
issue