$ git clone -n https://src.fedoraproject.org/rpms/rust-trybuild.git /var/lib/mock/f40-build-2644154-66497/root/chroot_tmpdir/scmroot/rust-trybuild
Cloning into '/var/lib/mock/f40-build-2644154-66497/root/chroot_tmpdir/scmroot/rust-trybuild'...
$ git fetch origin ee9773e9d156df0cfe712e1288c98b485e9c8d45:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-trybuild
 * [new ref]         ee9773e9d156df0cfe712e1288c98b485e9c8d45 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ee9773e Update to version 1.0.90; Fixes RHBZ#2269895