It turns that I need to set up my own cvsup server so I can deploy my fork elsewhere. Here comes how.

0. Create a dedicated user (‘jail user’).
1. Switch to the dedicated user, go into its home directory
2. Create a “base” directory. For example, mkdir base
3. Create a “sup” directory under “base” directory. The directory must be called “sup”
4. Create collection for it. Chdir into “sup”, then, mkdir [collection name]
5. In the “collection name” folder, create two files:

One is “releases”, for example, “cvs list=list.cvs prefix=prefix”. prefix is where the CVS repository located.
The other is “list.cvs” , each line contains a directory, for example, “upgrade src/bin”.

That’s all! Start cvsup under that user and enjoy! (cvsup -b [base directory])