  We investigate the interaction between compactness principles and guessing
principles in the Radin forcing extensions. In particular, we show that in any
Radin forcing extension with respect to a measure sequence on $\kappa$, if
$\kappa$ is weakly compact, then $\diamondsuit(\kappa)$ holds. This provides
contrast with a well-known theorem of Woodin, who showed that in a certain
Radin extension over a suitably prepared ground model relative to the existence
of large cardinals, the diamond principle fails at a strongly inaccessible
Mahlo cardinal. Refining the analysis of the Radin extensions, we consistently
demonstrate a scenario where a compactness principle, stronger than the
diagonal stationary reflection principle, holds yet the diamond principle fails
at a strongly inaccessible cardinal, improving a result from \cite{BN19}.
