$ git clone -n https://src.fedoraproject.org/rpms/rust2rpm.git /var/lib/mock/f39-build-1892119-42798/root/chroot_tmpdir/scmroot/rust2rpm
Cloning into '/var/lib/mock/f39-build-1892119-42798/root/chroot_tmpdir/scmroot/rust2rpm'...
$ git fetch origin 6c9e6a53b853fbaa88c435a96f900533497b77d0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust2rpm
 * [new ref]         6c9e6a53b853fbaa88c435a96f900533497b77d0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6c9e6a5 Update to version 25.0.3; Fixes RHBZ#2252419