I was able to test this now that the nest versions have been bumped. I just added this as an enum variant; since it’s an ssh library it might not be too specific to warrant being its own thing. Users might want to be able to detect this kind of error without having to parse a message.

It might be helpful to include the bad path in the error message (what SSH_AUTH_SOCK actually points to), but I don’t know enough about SSH to say whether that would be leaking info.

Nice patches, thanks! Sorry it took a little while.