$ git clone -n https://src.fedoraproject.org/rpms/rust-cfg-if.git /var/lib/mock/f45-build-40740-775/root/chroot_tmpdir/scmroot/rust-cfg-if
Cloning into '/var/lib/mock/f45-build-40740-775/root/chroot_tmpdir/scmroot/rust-cfg-if'...
$ git fetch origin 56fd39b2a66a1f793d98f7161024e01f9c1196b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-cfg-if
 * [new ref]         56fd39b2a66a1f793d98f7161024e01f9c1196b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 56fd39b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild