$ git clone -n https://src.fedoraproject.org/rpms/rust-vec1.git /var/lib/mock/f45-build-46017-830/root/chroot_tmpdir/scmroot/rust-vec1
Cloning into '/var/lib/mock/f45-build-46017-830/root/chroot_tmpdir/scmroot/rust-vec1'...
$ git fetch origin 5c0d6cb9ad408f0f4f3dca3513ecc9801613764d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-vec1
 * [new ref]         5c0d6cb9ad408f0f4f3dca3513ecc9801613764d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5c0d6cb Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild