G'day asspat2021,

Welcome to the Monastery.

Unfortunately, your post is rather sketchy and light on details; this makes it difficult for us to help you. Please don't take this as a rebuke; it's just a fact — this is your first post and I'll assume you simply didn't know what was needed. In the first instance, read "How do I post a question effectively?" which describes the sort of things to include: "will fail", "was working", and similar are not useful in isolation; state what the previous versions were, not that you just upgraded some unspecified earlier version; provide verbatim error messages within <code>...</code> tags, as opposed to prosaic paraphasing of such messages.

I used macOS for many years but abandoned it probably around 2017 or 2018 (all versions used were prior to Big Sur): I'm unable to provide any direct testing for Big Sur. I have located my last set of installation notes: I can reference that information where appropriate. I wrote a number of posts last year — "Re: Understanding Perl / Brew Perl and Cpan on macOS" and "Re: Upgrade to Big Sur perl issue" — please read these, as I won't be copying large tracts of existing text to this post, but will be referring to content therein.

In the absence of other information, here's roughly the steps I think you may need; although, possibly not all of them. This is subject to change depending upon subsequent information you might provide.

• If you are using the system Perl, you should stop doing that. If you've already made changes to that, you may need to reinstall it.
• Install Perlbrew.
• Use Perlbrew to install Perl 5.34.0 (the latest, stable release at the time of writing).
• Install any non-core (CPAN) modules you need using v5.34.
  • You should be able to do this with the core cpan utility.
  • There are other non-core utilities that I'm aware others prefer (e.g. cpanm and cpanp). You can use these if you prefer; of course, you'll still need cpan to install these (well, at least the first one). I don't use these so can't provide further help with that; other monks will certainly be able to provide information if it's wanted.
  • Unless you have some special reason for doing so, you should not need to do this by hand (i.e. the "perl Makefile.PL; make; make test; make install" incantation).
  • If you do decide to install by hand, make must be successful for make test to work. If make fails, running make test is pointless until you fix the make problems.
• Install "Tk 804.036" (again, the latest, stable release at the time of writing). Some notes:
  • Before doing this, ensure you have an X server running. In my personal notes, I indicate that "startx &" should be run; that may be different for you. The DISPLAY environment variable should have a value like ":0"; that's what I always see but, again, it could be different for you.
  • I completely agree with ++hippo's comments about using the the ancient 402.001 version (from last century). The current 804.036 version will have far greater Unicode support, which you seemed to indicate you wanted.
  • You should be able to use the core cpan utility for this as well; that's all I've ever needed.
  • You will occasionally get some test failures. Mostly these are problems in one or more *.t files and not an issue with Tk itself. If this happens, go ahead and force installation: this typically works.
  • Run the widget demo (I usually do this in the background: widget &) and do some basic checks. Run your "word processor" and any other Tk applications you use: check these still work.

I've successfully installed many versions of Tk, on many versions of Perl, on many OSes; failures have been very rare. My last, on macOS, was Perl 5.26 and Tk 804.034 (that required a force install after 1 subtest failure). My current, on Cygwin, is Perl 5.34 and Tk 804.036 (that also required a force install): it's been running without any problems for about the last six months. Using that combination, I've posted quite a few complete working Tk scripts on this site and have used it for a far greater number, with subtantially more complexity, for my own personal use.