repotool checkout does not work for CVS
Running repotool checkout on a CVS repository fails with an error that the CVSROOT directory does not exist.
$ make cron-checkout
cd cron-mirror >/dev/null; repotool checkout ../cron-checkout
cvs [checkout aborted]: /temp/cvs-conversion/cron-new/CVSROOT: No such file or directory
Prior to repotool, the conversion.mk file used the -c option to cvssync to make the mirror usable as a CVS repository.