$ git clone -n https://src.fedoraproject.org/rpms/buildstream.git /var/lib/mock/f39-build-1918009-42931/root/chroot_tmpdir/scmroot/buildstream
Cloning into '/var/lib/mock/f39-build-1918009-42931/root/chroot_tmpdir/scmroot/buildstream'...
$ git fetch origin ff579e39ec2935fe69038c72bdb71187c4e82593:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/buildstream
 * [new ref]         ff579e39ec2935fe69038c72bdb71187c4e82593 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ff579e3 Backport a patch to fix build for Python 3.12