$ git clone -n https://src.fedoraproject.org/rpms/gnome-shell.git /var/lib/mock/f41-build-854113-166804/root/chroot_tmpdir/scmroot/gnome-shell
Cloning into '/var/lib/mock/f41-build-854113-166804/root/chroot_tmpdir/scmroot/gnome-shell'...
$ git fetch origin 5921872a1ce3299c5ed82c6761cb8abc36af956a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gnome-shell
 * [new ref]         5921872a1ce3299c5ed82c6761cb8abc36af956a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5921872 Update to 47.0