$ \textbf{hg init hidden-example}
$ \textbf{cd hidden-example}
$ \textbf{mkdir empty}
$ \textbf{touch empty/.hidden}
$ \textbf{hg add empty/.hidden}
$ \textbf{hg commit -m 'Manage an empty-looking directory'}
$ \textbf{ls empty}
$ \textbf{cd ..}
$ \textbf{hg clone hidden-example tmp}
updating working directory
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ \textbf{ls tmp}
empty
$ \textbf{ls tmp/empty}