$ git clone -n https://src.fedoraproject.org/rpms/rust-num-bigint.git /var/lib/mock/f45-build-43432-803/root/chroot_tmpdir/scmroot/rust-num-bigint
Cloning into '/var/lib/mock/f45-build-43432-803/root/chroot_tmpdir/scmroot/rust-num-bigint'...
$ git fetch origin 02e0d6215955b851045909f8681d8bb563048a59:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-num-bigint
 * [new ref]         02e0d6215955b851045909f8681d8bb563048a59 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 02e0d62 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild