Commands are invoked as continuations chained via the "thenWithState" future utility; see here. "thenWithState" is noexcept annotated, and invokes the provided continuation inline via makeReadyFutureWith; see here. makeReadyFutureWith catches any DBExceptions thrown by the continuation and converts them to Statuses; see here, but does not catch other (i.e. system/std) exceptions. That means if a non-db exception (i.e. from an STL container or type) is thrown and uncaught anywhere in the command execution process, during stack unwinding it could bubble up to the noexcept-annotated thenWithState, which will result in process termination with minimal diagnostics available.