We’ve seen in this section that in Go, having a nil receiver is allowed, and an interface converted from a nil pointer isn’t a nil interface. For that reason, when we have to return an interface, we should return not a nil pointer but a nil value directly. Generally, having a nil pointer isn’t a desirable state and means a probable bug.
We saw an example with errors throughout this section because this is the most common case leading to this error. But this problem isn’t only tied to errors: it can happen with any interface implemented using pointer receivers.
