[Rd] cvs diff not working on anonymous cvs (PR#4907)

[bjg at network-theory.co.uk]

Full_Name: Brian Gough
Version: anonymous cvs
OS: Debian GNU/Linux 3.0
Submission from: (NULL) (80.46.234.10)


After successfully checking out the source tree following the instructions on
http://anoncvs.r-project.org/ I can run cvs update commands successfully but not
cvs diff.

bjg|debian> cvs update
cvs server: Updating .
cvs server: Updating afm
....
bjg|debian> cvs diff -r R-1-7-0 README 
cvs [server aborted]: cannot write /cvs/CVSROOT/val-tags: Permission denied

Thanks for making CVS available (very useful -- I wiped out some work several
times when using Rsync!)