As tidy doesn't explicitly set :follow the results may vary if the target dir is a symlink. For example, if trying to tidy /etc/init.d which is a symlink to /etc/rc./d/init.d on CentOS 6/7 it won't work. -
However tidying /etc/init.d/ (trailing slash) will work-.
Instead tidy should explicitly set :links => :follow or at least have it configurable (or both).