$ git clone -n https://src.fedoraproject.org/rpms/rust-minus.git /var/lib/mock/f39-build-1879953-42749/root/chroot_tmpdir/scmroot/rust-minus
Cloning into '/var/lib/mock/f39-build-1879953-42749/root/chroot_tmpdir/scmroot/rust-minus'...
$ git fetch origin 60189755e1c15a0ac0deb2095eb44014c1e91d6f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-minus
 * [new ref]         60189755e1c15a0ac0deb2095eb44014c1e91d6f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6018975 Update to version 5.5.0; Fixes RHBZ#2251603