That tends to be the biggest cop out excuse for libraries. Just do a major version release. The fact this library lies about the encodingis extremely problematic and causes numerous bugs. Any program currently using this library is already incorrect because of this behavior. Actually exposing the problem makes it easier for people to fix.
in reply to subject of https://hyp.is/VeTJlpN0Ee2mNKOVyQ-B5g/github.com/mikel/mail/issues/902