fix(fleet): the who recipe reported nobody on a machine full of users

[ralyodio]

who || w was wrong, and wrong in a way that reads as correct.

who reads utmp, which on a systemd host with pty-less SSH sessions is routinely empty while people are very much logged in — and it exits 0 either way. So || never reached w, and the recipe returned nothing at all.

Confirmed on a live host:

$ who ; echo "exit=$?"        # zero lines
exit=0
$ w
 13:57:34 up 9:53,  2 users,  load average: 2.98, 3.34, 3.14
 anthony   172.12.140.170   13:55   0.00s  0.02s sshd-session: anthony [priv]

The failure mode is empty output, not a non-zero exit, and || cannot see the difference.

Fix

Fall back on emptiness rather than on exit status, and say so when there genuinely is nobody:

found=$(who 2>/dev/null)
[ -z "$found" ] && found=$(w -h 2>/dev/null)
if [ -n "$found" ]; then printf '%s\n' "$found"
else echo "no interactive logins on this host"; fi

That last branch matters. A status command that prints nothing is indistinguishable from a broken one — which is exactly how this got reported.

The wider hunch, checked

The report suspected output had gone missing for other built-ins too. It hasn't — I ran all five reporting recipes through the real fleet path against a live host before touching anything:

Recipe	stdout
check-updates	8 lines
disk	6 lines
uptime	1 line
reboot-required	1 line
who	0 lines

So nothing in the streaming path is dropping anything; who was the only silent one. Worth saying plainly rather than "fixed it".

Tests

Adds the invariant that was actually broken — no reporting recipe may produce empty output — plus two asserting who branches on emptiness rather than exit status. 498 tests, up from 491.

🤖 Generated with Claude Code

https://claude.ai/code/session_01UeSWg1Czsb2Lwxj8vHUnA4