$ git clone -n https://src.fedoraproject.org/rpms/rust-local-channel.git /var/lib/mock/f45-build-43035-799/root/chroot_tmpdir/scmroot/rust-local-channel
Cloning into '/var/lib/mock/f45-build-43035-799/root/chroot_tmpdir/scmroot/rust-local-channel'...
$ git fetch origin 52dc2f8dc8eba832b0973da9b8cb7a3f4cd9fac7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-local-channel
 * [new ref]         52dc2f8dc8eba832b0973da9b8cb7a3f4cd9fac7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 52dc2f8 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild