$ git clone -n https://src.fedoraproject.org/rpms/rust-postcard-derive.git /var/lib/mock/f45-build-43928-809/root/chroot_tmpdir/scmroot/rust-postcard-derive
Cloning into '/var/lib/mock/f45-build-43928-809/root/chroot_tmpdir/scmroot/rust-postcard-derive'...
$ git fetch origin 7ef7f95bd18d31d4cfe2029d46b03da1b3b93656:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-postcard-derive
 * [new ref]         7ef7f95bd18d31d4cfe2029d46b03da1b3b93656 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7ef7f95 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild