I went through those, and didn't see anything interesting. Perl-v reported 5.24.1 each time; perl-M had no output each time.

So I set up a script that used used each of those modules in turn, printing its name beforehand, so I could see where it was having a problem. And it ran fine.

So I created a script that just had the use statements from the broken script, and it failed. So I removed a line at a time to see which one was causing XML::RSS to break.

It was Try. Moving that to be used after XML::RSS seems to have made it work. Thanks for the help :)

I have no idea why that might have broken it, and I'll spend some more time digging into it, but for now... it seems to be working.