kmd --cache fails when using nfs protocol

[xjules]

The cache can cause errors when calling the following the nfs protocol copy command:

shell(f"cp --recursive --symbolic-link {path} {filename}")

The error is as follows:

...
cp: ‘/project/res/komodo/repository/boost-1.64.0/include/boost/memory_order.hpp’ and ‘boost-devel-1.64.0/boost-1.64.0/include/boost/memory_order.hpp’ are the same file
cp: ‘/project/res/komodo/repository/boost-1.64.0/include/boost/metaparse.hpp’ and ‘boost-devel-1.64.0/boost-1.64.0/include/boost/metaparse.hpp’ are the same file
cp: ‘/project/res/komodo/repository/boost-1.64.0/include/boost/mpi.hpp’ and ‘boost-devel-1.64.0/boost-1.64.0/include/boost/mpi.hpp’ are the same file
cp: ‘/project/res/komodo/repository/boost-1.64.0/include/boost/multi_array.hpp’ and ‘boost-devel-1.64.0/boost-1.64.0/include/boost/multi_array.hpp’ are the same file
...

[berland]

When/if #351 is merged, this is no longer a bug, since it is no longer called a cache.