$ git clone -n https://src.fedoraproject.org/rpms/jam.git /var/lib/mock/f40-build-790505-136598/root/chroot_tmpdir/scmroot/jam
Cloning into '/var/lib/mock/f40-build-790505-136598/root/chroot_tmpdir/scmroot/jam'...
$ git fetch origin 9516edf835504e898c452cd919057a11f775db93:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/jam
 * [new ref]         9516edf835504e898c452cd919057a11f775db93 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9516edf fix argv handling, fix license tag