$ git clone -n https://src.fedoraproject.org/rpms/thunderbird.git /var/lib/mock/f40-build-782780-132277/root/chroot_tmpdir/scmroot/thunderbird
Cloning into '/var/lib/mock/f40-build-782780-132277/root/chroot_tmpdir/scmroot/thunderbird'...
$ git fetch origin 31767572cb1ec7ac3859196c34e302603ca39e3f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/thunderbird
 * [new ref]         31767572cb1ec7ac3859196c34e302603ca39e3f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3176757 Update to 115.8.0