FAQ

Permission Denied to root's Home

This, or similar things:

$ sudo mole dig whatever
fatal mkdir /root/.mole: permission denied

The root cause is that sudo is setting the HOME environment variable to /root. By default, sudo should not modify the HOME from the original user's setting but there are a few configuration variables in /etc/sudoers that affect this. See the sudo man page about the -H option, env_reset, set_home and always_set_home.