FreeBSD# portdowngrade nvidia-driver

portdowngrade 0.6 by Heiner Eichmann
Please note, that nothing is changed in the ports tree
unless it is explicitly permitted in step 6!

Seeking port nvidia-driver ... found: x11/nvidia-driver

Step 1: Checking out port from CVS repository
No CVS root directory set! Please use the -s option.

cvs checkout: No CVSROOT specified!  Please use the `-d' option
cvs [checkout aborted]: or set the CVSROOT environment variable.
portdowngrade error: Can not check out port x11/nvidia-driver

An error had occured. If this was an cvs error, try another cvs server.
If this was an cvs login error, try the -o option.