Why does "last" fail on Alpine with "last couldn't open file '/dev/null/wtmp' "?

Question

Why is the last command failing on my fresh install of Alpine 3.12?

$ last
couldn't open file '/dev/null/wtmp': Not a directory

wtmp begins Thu Jan  1 00:00

(on a Linode server if that matters)

Answer 1

That's a long known issue. Alpine uses libmusl instead of glibc. It seems that

musl does not use or even support /dev/null/utmp or /dev/null/wtmp (and nothing appears to get written to /var/log/wtmp); so I guess there might not be a way to fix this.

https://gitlab.alpinelinux.org/alpine/aports/-/issues/3282#note_15597

There is an open issue for it on the Alpine Linux page and apparently it is a milestone for the 3.14.0 release of Alpine Linux. Until than there is probably no workaround for this.