Mark Hobley wrote:

>> this document explains how to mirror the gentoo source repository:
>> http://www.gentoo.org/doc/en/source_mirrors.xml
>
> That website doesn't actually give the rsync command to use.

That document is for setting up a *public* source mirror. And it tells you
that you have to sync with ftp.ussg.iu.edu::gentoo-distfiles, not with just
any mirror.

If you just want to have the sources for the packages, remember that you can
get *any* source package just by using emerge -f, without the need to set
up a full source mirror.

Also remember that if you modify the sources in any way you cannot install
them using emerge unless you regenerate the ebuild and digests for the
packages first. Read the developer handbook for more info.