DBD::CSV attempt to free unreferenced scalar during globaldestruction (2 messages)

Hello,

I'm here looking for help with an issue I'm having with DBD::CSV.

Specifically, I'm attempting to use the 'after_parse' callback to handle a
csv file with a data defined variable number of columns and hit a warning
on an attempt to free unreferenced scalar during global destruction.

I've prepared a minimal example at
https://gist.github.com/kiwiroy/fa0c737ff3f298cb064e554505bc4495 so show
the issue. The two test scripts process the 'input.csv' with Text::CSV and
DBD::CSV respectively and only the latter exhibits the behaviour.

It appears to be 5.24.0 specific. I'm using default perlbrew built perls.

Is there something I'm missing or doing wrong?

Thanks in advance.

Roy