$ git clone -n https://src.fedoraproject.org/rpms/asymptote.git /var/lib/mock/f40-build-2195251-51522/root/chroot_tmpdir/scmroot/asymptote
Cloning into '/var/lib/mock/f40-build-2195251-51522/root/chroot_tmpdir/scmroot/asymptote'...
$ git fetch origin 1c13969d93f7c7edd41260634ee4ed252dbdc37d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/asymptote
 * [new ref]         1c13969d93f7c7edd41260634ee4ed252dbdc37d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1c13969 Minor spec file cleanups