$ git clone -n https://src.fedoraproject.org/rpms/rust-const_format_proc_macros.git /var/lib/mock/f42-build-side-1-3539500-46565/root/chroot_tmpdir/scmroot/rust-const_format_proc_macros
Cloning into '/var/lib/mock/f42-build-side-1-3539500-46565/root/chroot_tmpdir/scmroot/rust-const_format_proc_macros'...
$ git fetch origin 64e5b291ba65c697974bea5a5bd1c4179e0dfdac:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-const_format_proc_macros
 * [new ref]         64e5b291ba65c697974bea5a5bd1c4179e0dfdac -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 64e5b29 Update to version 0.2.34; Fixes RHBZ#2330921