$ git clone -n https://src.fedoraproject.org/rpms/rust-ocb3.git /var/lib/mock/f45-build-43501-803/root/chroot_tmpdir/scmroot/rust-ocb3
Cloning into '/var/lib/mock/f45-build-43501-803/root/chroot_tmpdir/scmroot/rust-ocb3'...
$ git fetch origin 931c2ecc7982fe77e5c35b0c57d906d7ab987e23:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ocb3
 * [new ref]         931c2ecc7982fe77e5c35b0c57d906d7ab987e23 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 931c2ec Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild