To be honest I did understand what was wrong from the error message on first read, despite not knowing ruby (but probably aided by experience in other languages

To be honest I did understand what was wrong from the error message on first read, despite not knowing ruby (but probably aided by experience in other languages with similar patterns). I think what the distant grandparent was noticing is valid though: the error message is accurately but tangential to the reason for the error. Sure, you can figure it out. Probably you can figure it out without needing to be a great master of the language. But to criticize somebody for wondering whether an error message could be more informative/relevant, when that is clearly possible, I find galling.