In this paper, we study spherical gravitational collapse of inhomogeneous
    pressureless matter in a well-defined $n \rightarrow4$d limit of the
    Einstein-Gauss-Bonnet gravity. The collapse leads to either a black hole or a
    massive naked singularity depending on time of formation of trapped surfaces.
    More precisely, horizon formation and its time development is controlled by
    relative strengths of the Gauss-Bonnet coupling $(\lambda)$ and the
    Misner-Sharp mass function $F(r,t)$ of collapsing sphere. We find that, if
    there is no trapped surfaces on the initial Cauchy hypersurface and $F(r,t)<
    2\sqrt{\lambda}$, the central singularity is massive and naked. When this
    inequality is equalised or reversed, the central singularity is always censored
    by spacelike/timelike spherical marginally trapped surface of topology
    $S^{2}\times \mathbb{R}$, which eventually becomes null and coincides with the
    event horizon at equilibrium. These conclusions are verified for a wide class
    of mass profiles admitting different initial velocity conditions. Hence, our
    result implies that the $4$d Einstein-Gauss-Bonnet generically violates the
    cosmic censorship conjuncture. Further implications of this violation from the
    perspective of visibility of causal signals from the spacetime singularity are
    also discussed.

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