[We](https://github.com/warewulf/warewulf) use `copy.DirCopy` and have encountered a behavior that, if the source contains sockets, the copy operation fails with an error of the form: ``` lchown /var/lib/warewulf/chroots/gpuslurm/rootfs/run/user/0/gnupg/d.kg8ijih5tq41ixoeag4p1qup/S.gpg-agent: no such file or directory ``` Could `copy.DirCopy` be updated to ignore sockets in the source in stead? Reported for Warewulf at https://github.com/warewulf/warewulf/issues/892