$ git clone -n https://src.fedoraproject.org/rpms/libtnc.git /var/lib/mock/f40-build-2219961-52649/root/chroot_tmpdir/scmroot/libtnc
Cloning into '/var/lib/mock/f40-build-2219961-52649/root/chroot_tmpdir/scmroot/libtnc'...
$ git fetch origin b4163ccf9a1b5737fd188e00429ac36291000264:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libtnc
 * [new ref]         b4163ccf9a1b5737fd188e00429ac36291000264 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b4163cc Set build_type_safety_c to 0 (#2154692)