Marc Branchaud [off-list ref] writes:
It's FreeBSD 7.2, which I know is an obsolete version but I'm not able to
upgrade the machine. I believe FreeBSD's sh is, or is derived from, dash.
Dash has been the default '/bin/sh' for Ubuntu for quite a long time
now[1] in spite of repeated reports of compatibility problems[2].
Phil
[1] https://wiki.ubuntu.com/DashAsBinSh
[2] https://bugs.launchpad.net/ubuntu/+source/dash/+bug/141481