$ git clone -n https://src.fedoraproject.org/rpms/libestr.git /var/lib/mock/f45-build-16127-483/root/chroot_tmpdir/scmroot/libestr
Cloning into '/var/lib/mock/f45-build-16127-483/root/chroot_tmpdir/scmroot/libestr'...
$ git fetch origin 6e4a8cd401223e5a7578b643ff9d600d78bcdae6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libestr
 * [new ref]         6e4a8cd401223e5a7578b643ff9d600d78bcdae6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6e4a8cd Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild