$ git clone -n https://src.fedoraproject.org/rpms/rust-xz2.git /var/lib/mock/f45-build-46259-832/root/chroot_tmpdir/scmroot/rust-xz2
Cloning into '/var/lib/mock/f45-build-46259-832/root/chroot_tmpdir/scmroot/rust-xz2'...
$ git fetch origin 076c16c3b027126debbad8264845522f27e144f0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-xz2
 * [new ref]         076c16c3b027126debbad8264845522f27e144f0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 076c16c Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild