self-upgrade failure

[nigelhorne]

This is a standard machine, I've done nothing and this has failed since initial installation:

$ perlbrew self-upgrade
Can't exec "/tmp/perlbrew": No such file or directory at /home/njh/perl5/perlbrew/bin/perlbrew line 2656.
Use of uninitialized value $new_version in scalar chomp at /home/njh/perl5/perlbrew/bin/perlbrew line 2657.
Use of uninitialized value $new_version in pattern match (m//) at /home/njh/perl5/perlbrew/bin/perlbrew line 2658.
Unable to detect version of new perlbrew!
$ uname -a
FreeBSD redacted.site.com 14.0-RELEASE-p3 FreeBSD 14.0-RELEASE-p3 #0: Mon Dec 11 04:56:01 UTC 2023     root@amd64-builder.daemonology.net:/usr/obj/usr/src/amd64.amd64/sys/GENERIC amd64
$