I didn't run your script because I installed p5-tk with MacPorts and got a display error, I think because I have to install xquartz and I'm not interested in doing that right now on this machine. I did just now run the below though, with a 5.34 perl installed via MacPorts on an M1 mac:

% uname -a
Darwin ... 21.6.0 Darwin Kernel Version 21.6.0: Mon Apr 24 21:11:17 PD
+T 2023; root:xnu-8020.240.18.701.5~1/RELEASE_ARM64_T6000 arm64

% perl -le 'print 12.99 * 16.25'
211.0875
[download]

I don't know about xquartz (as I said I don't own a Mac so I'm not familiar with what xquartz is), but you would have to install xorg from MacPorts like this:

sudo port install xorg
sudo port install p5-tk

that's taken from the macOS installation instructions for my application, these instructions were written for me by another macOS user (with an Intel Mac though).
http://obd-amigos.linuxtech.net/files/00-How_to_install_OBD_Amigos_on_macOS.html

Since these are MacPorts packages, isn't it quite easy to uninstall them cleanly again after the test, if you have no need for them?

Thanks for the one-liner test but unfortunately it's not as simple as that to trigger this issue, I also gave the user of my application a similar one-liner (but with eval) at first, without triggering the issue. I have a feeling that Tk is needed to trigger the issue.

I have a feeling that Tk is needed to trigger the issue.

You're saying that you feel it's a bug in Tk.
If it is a bug in Tk, then I would think it's a bug that's being exposed by some specific rarity in the users perl configuration or system.

In any case, I think the first thing to obtain and peruse is the perl -V output from the user's m1/m2 system.

Cheers,
Rob

Hi, I did do `sudo port install xorg` but got the same display error as earlier running your Tk program and didn't proceed installing additional dependencies, apologies.