$ git clone -n https://src.fedoraproject.org/rpms/calls.git /var/lib/mock/f38-build-side-42-init-devel-566257-25898/root/chroot_tmpdir/scmroot/calls
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-566257-25898/root/chroot_tmpdir/scmroot/calls'...
$ git fetch origin 0d6bf1478eb2394a20f4bd4ae94714bdac28e916:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/calls
 * [new ref]         0d6bf1478eb2394a20f4bd4ae94714bdac28e916 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0d6bf14 C99 compatibility fix