> Does not prevent chdir()ing up from the target directory.

Perhaps not, but since you can't examine the contents of the
directory, this seems like a non-problem.

Unfortunately, most unix applications and particularly build
environments assume that people will have a umask of 002 and that most
directories on the system will have permissions of 0755, so setting up
a more restrictive permission policy tends to fail in obscure and
annoying ways.   Sigh.

			       _MelloN_