$ git clone -n https://src.fedoraproject.org/rpms/rust-pkcs1.git /var/lib/mock/f45-build-43876-807/root/chroot_tmpdir/scmroot/rust-pkcs1
Cloning into '/var/lib/mock/f45-build-43876-807/root/chroot_tmpdir/scmroot/rust-pkcs1'...
$ git fetch origin c4d203acab82bc52dc6a04f384c28a0684bf444e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pkcs1
 * [new ref]         c4d203acab82bc52dc6a04f384c28a0684bf444e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c4d203a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild