Errors raised in a resolver — let's take

ErrValueError:  "Field '$1' cannot be resolved: \"$2\"" % [msg[0], msg[1]]

get they type after a RespResult holding a message string and the place where they're occur.
Comparing the situation to other GraphQL implementations, I'm wondering if there's a way to provide custom error messages ?
Perhaps raising an other exception when an unspecified error kind is met,
and adding a custom one with no formatting along the lines ?

Also, is it possible to stack them in a sequence before returning ?
I tried with ctx.errors.add but this is a user context, not the calling one (if that makes sense, but I'm still building the mental picture of the mechanisms). If not I would gladly PR on that.