encoding error / windows traceback

[meejah]

I'm not entirely sure what's going on here, but on a GitHub Actions windows runner, I'm seeing this from eliot-tree:

Traceback (most recent call last):
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\runpy.py", line 194, in _run_module_as_main
    return _run_code(code, main_globals, None,
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\runpy.py", line 87, in _run_code
    exec(code, run_globals)
  File "C:\hostedtoolcache\windows\Python\3.8.10\x64\Scripts\eliot-tree.exe\__main__.py", line 7, in <module>
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\site-packages\eliottree\_cli.py", line 308, in main
    display_tasks(
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\site-packages\eliottree\_cli.py", line 116, in display_tasks
    render_tasks(
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\site-packages\eliottree\_render.py", line 289, in render_tasks
    write(format_tree(task, _format_node, _get_children, options))
  File "c:\hostedtoolcache\windows\python\3.8.10\x64\lib\encodings\cp1252.py", line 19, in encode
    return codecs.charmap_encode(input,self.errors,encoding_table)[0]
UnicodeEncodeError: 'charmap' codec can't encode characters in position 38-40: character maps to <undefined>

I've attached the eliot.log from the run (but when using eliot-tree on it on a Linux machine, I do not see the above error).