At the top of the env.py file, Jython and IronPython are recognized besides CPython and PyPy. However, line 88 (linked in this issue) assumes that coveragepy runs on either PyPy or CPython - if CPYTHON is False (as it is on e.g. Jython and IronPython, but also on GraalPy), this raises NameError: name 'PYPYVERSION' is not defined

https://github.com/nedbat/coveragepy/blob/a3c8683f8e46590c145e16c1aebf7a7766513890/coverage/env.py#L88