CVS commands need to know where the CVS repository is that they need to access.
Once the working copy is checked out, the repository location is stored in a file Root inside of the CVS subdirectory of each directory of your working copy.
Until the working copy is available - and with some CVS commands - you have to tell the commands where the repository is located. Two methods:
Set the CVSROOT environment variable to the repository location. In the Linux bash shell, this can be done with one of the following examples:
$ export CVSROOT=/home/cvsroot $ export CVSROOT= dyork@mail.e-smith.com:/home/e-smith/files/ibays/cvsroot
Supply the -d global option to a CVS command, as in:
cvs -d dyork@mail.e-smith.com:/home/e-smith/files/ibays/cvsroot co documentation