I would probably do these in a slightly safer manner:
emerge --unmerge pam-login && emerge --update shadow
emerge --unmerge utempter && emerge --update libutempter
You are right, I didn't think about that (maybe because my machine has never crashed)
I would probably do these in a slightly safer manner:
emerge --unmerge pam-login && emerge --update shadow
emerge --unmerge utempter && emerge --update libutempter