$ git clone -n https://src.fedoraproject.org/rpms/rust-serial_test.git /var/lib/mock/f41-build-side-1-3134914-39764/root/chroot_tmpdir/scmroot/rust-serial_test
Cloning into '/var/lib/mock/f41-build-side-1-3134914-39764/root/chroot_tmpdir/scmroot/rust-serial_test'...
$ git fetch origin 7f280f098ec912a0a9fec92041a42d0375872719:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serial_test
 * [new ref]         7f280f098ec912a0a9fec92041a42d0375872719 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7f280f0 Update to version 3.2.0; Fixes RHBZ#2324743