$ git clone -n https://src.fedoraproject.org/rpms/SimGear.git /var/lib/mock/f38-build-side-42-init-devel-575559-26000/root/chroot_tmpdir/scmroot/SimGear
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-575559-26000/root/chroot_tmpdir/scmroot/SimGear'...
$ git fetch origin fb3015d92964e701fcfe5c0954ffcf0966759c35:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/SimGear
 * [new ref]         fb3015d92964e701fcfe5c0954ffcf0966759c35 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb3015d new upstream release