The Alpine/musl runtime can't exec our glibc-linked binary —
'exec /usr/local/bin/finger: no such file or directory'. The
recent syslog change pulls in fortify-source _chk symbols and
fcntl64 that musl doesn't provide even with gcompat. Matching
the runtime base to the builder (ubuntu:24.04) makes the image
reliably runnable; ship netcat-openbsd for the healthcheck.
The Alpine runtime stage uses BusyBox nc, which has no -z flag, and
'localhost' resolves to ::1 while finger only binds 0.0.0.0:79. Both
combined caused every healthcheck to fail (35k+ failing streak on
mammut). Use '-w 1 127.0.0.1 79 < /dev/null' instead.