  We study a three-dimensional single-band repulsive Hubbard model at weak
coupling. We establish the superconducting phase diagram in the parameter space
of the chemical potential and the out-of-plane hopping strength. The model
continuously connects the Hubbard model in two and three dimensions. We confirm
previously-established results in these limits, and identify a rich structure
of competing order parameters in between. Specifically, we find five types of
$p$- and $d$-wave orders. In several regions of the phase diagram, even when
the Fermi surface is a corrugated cylinder, the ground state is a
time-reversal-symmetry-breaking superconductor with nodes, i.e. a Weyl
superconductor.
