$ git clone -n https://src.fedoraproject.org/rpms/fntsample.git /var/lib/mock/f45-build-9121-399/root/chroot_tmpdir/scmroot/fntsample
Cloning into '/var/lib/mock/f45-build-9121-399/root/chroot_tmpdir/scmroot/fntsample'...
$ git fetch origin 19eb97319047bd8681a4698dc38a291d7b8cef21:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fntsample
 * [new ref]         19eb97319047bd8681a4698dc38a291d7b8cef21 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 19eb973 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild