Hi,
Which source tree root are you referring to?
The sources for the current Fedora package. A source rpm has a tarball of the sources, and optionally a series of patch files relative to that "upstream" tarball.
Not sure where to find those sources though, I'm not too familiar with Fedora procedures.
Here's the latest build:
http://koji.fedoraproject.org/koji/buildinfo?buildID=148721
The .src.rpm contains a specfile (that describes which patches to apply on the tarball) and the tarball and patches.
If you want to unpack the .src.rpm on a machine that isn't running Fedora, I think you'll need rpm2cpio and cpio:
rpm2cpio squeak-vm-3.10.5-2.fc11.src.rpm | cpio -idmv
Thanks,
- Chris.