When candidates are clearly unable to finish the interview problems even with hints and help, I conclude the technical interview early and transition to an informal discussion of their career, progress, and goals. I don’t think it’s worth compromising your technical interview standards just because you like a candidate. You have those standards for a reason. However, having a friendly conversation with the candidate can at least leave them on good terms and can give them an opportunity to get some light feedback on what’s expected from the job and where they can go to learn it.