$ git clone -n https://src.fedoraproject.org/rpms/breeze-gtk.git /var/lib/mock/f42-build-side-1-3562223-46722/root/chroot_tmpdir/scmroot/breeze-gtk
Cloning into '/var/lib/mock/f42-build-side-1-3562223-46722/root/chroot_tmpdir/scmroot/breeze-gtk'...
$ git fetch origin 7541a08484d5ff0b8322a480b6210e2c5d12445a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/breeze-gtk
 * [new ref]         7541a08484d5ff0b8322a480b6210e2c5d12445a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7541a08 6.4.0