$ git clone -n https://src.fedoraproject.org/rpms/toxcore.git /var/lib/mock/f40-build-754009-117559/root/chroot_tmpdir/scmroot/toxcore
Cloning into '/var/lib/mock/f40-build-754009-117559/root/chroot_tmpdir/scmroot/toxcore'...
$ git fetch origin 86f9046060a0c8d8aa3dc23fefa022124955eba6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/toxcore
 * [new ref]         86f9046060a0c8d8aa3dc23fefa022124955eba6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 86f9046 rebuild for new libsodium