$ git clone -n https://src.fedoraproject.org/rpms/libtalloc.git /var/lib/mock/f42-build-side-1-3588362-46945/root/chroot_tmpdir/scmroot/libtalloc
Cloning into '/var/lib/mock/f42-build-side-1-3588362-46945/root/chroot_tmpdir/scmroot/libtalloc'...
$ git fetch origin 57e8d262a2e5129f76943ead61b41892d5461df9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtalloc
 * [new ref]         57e8d262a2e5129f76943ead61b41892d5461df9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 57e8d26 Package LICENSE file