The issue is here. It seemed like an easy fix to me: If I go into the operator<< override in types.cpp, I can just add/change some logic to create the format suggested in #41772.
The original post says “The change should be made in both IRPrinter and IRParser, since there are tests checking that we can parse what we print. It is expected that such change would break lots of tests, for instance test/test_jit.py - we will need to update all the failing tests as well.” So,  part of the issue is fixing any relevant tests.
Since I posted my issue yesterday, I’ve come to a slightly better understanding of how run_test.py works. I see where in the code the tmp directory is made, and I’m able to move further in the right direction by putting a few tests (e.g. test_cpp_extensions_aot_no_ninja) after the --exclude option. I still have a lot of questions, though…I installed Ninja per the PyTorch build instructions, so why is test_cpp_extensions_aot_no_ninja even being called? Is it okay to just exclude tests like this if it seems like they’re not relevant to my fix?
Also, another issue: I can’t finish running the test suite on my MacBook even with some tests excluded. Python maxes out the CPU and the program shuts down. I followed the installation steps for Mac here, replacing any instances of install with develop. Is there something else you need to do to physically run the tests? (I’ve read some stuff about ssh-ing into a remote GPU, but that seemed kind of extreme.) If so, I’d love to add some extra info to the documentation!