  We show that the numerically exact bold-line diagrammatic theory for the $2d$
Hubbard model exhibits a non-Fermi-liquid (NFL) strange metal state, which is
connected to the SYK NFL in the strong-interaction limit. The solution for the
doped system features the expected phenomenology with the NFL near half-filling
at strong couplings and in a wide temperature range enclosed by the atomic
state at high temperatures and a Fermi liquid at low temperatures. We
demonstrate, however, that this behavior in the weakly doped regime is due to
the unphysical branch of the Luttinger-Ward functional. On the other hand, our
analysis shows that the NFL physics is realized at larger doping.
