Tom:
...
> What is the recommended alternative way to create a sub-directory of
> /var/run on bootup for non-daemon software?

Don't know about "recommended", but you can

. prepend your cron script like (or have a wrapper):

if [ ! -d / ]; then mkdir -p /var/run/barman; fi
<rest of cron script>

. in the crontab have a boot entry:

@reboot <script like above to setup /var/run/barman>

. check which init.d script which sets up /var/run and which starts
cron, and add a script that starts somewhere between thoose two that
sets up /var/run/barman

Regards,
/Karl Hammar

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