TypeError: 'Forward' object is not subscriptable

[hhslepicka]

• doctr_versions_menu version: 0.2.0
• Python version: 3.6.7
• Operating System: Linux

Description

Upload of docs started to fail with doctr-versions-menu 0.2.0.

What I Did

CI started failing with doctr-versions-menu 0.2.0 and Python 3.6.

Traceback (most recent call last):
361  File "/home/travis/virtualenv/python3.6.7/bin/doctr-versions-menu", line 8, in <module>
362    sys.exit(main())
363  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/click/core.py", line 829, in __call__
364    return self.main(*args, **kwargs)
365  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/click/core.py", line 782, in main
366    rv = self.invoke(ctx)
367  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/click/core.py", line 1066, in invoke
368    return ctx.invoke(self.callback, **ctx.params)
369  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/click/core.py", line 610, in invoke
370    return callback(*args, **kwargs)
371  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/doctr_versions_menu/cli.py", line 242, in main
372    label_specs=label,
373  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/doctr_versions_menu/version_data.py", line 52, in get_version_data
374    latest = resolve_folder_spec(latest_spec, groups)[-1]
375  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/doctr_versions_menu/folder_spec.py", line 154, in resolve_folder_spec
376    spec_list = _parse_folder_spec(spec, groups, sort_key=sort_key)
377  File "/home/travis/virtualenv/python3.6.7/lib/python3.6/site-packages/doctr_versions_menu/folder_spec.py", line 121, in _parse_folder_spec
378    + Optional(SliceSpec)
TypeError: 'Forward' object is not subscriptable

More details here: https://travis-ci.com/github/hhslepicka/testproject1234/jobs/366798126#L360-L378

[goerz]

Thanks for reporting! I'll look into it...

[hhslepicka]

@goerz i just found the issue. We need a strict version on pyparsing.
Leaving it open allows for old versions that are no longer compatible with doctr-versions-menu.

Would you mind to add a more strict version at the setup.py to avoid this issue?

[goerz]

So it looks like the broken CI had pyparsing 2.4.0, and the one that works has pyparsing 2.4.7... I'll see if I can nail down what the minimum version requirement is, or maybe I can even find some fix that will make it work on all versions.

[hhslepicka]

Awesome! That was exactly the issue. Thank you!
For now I updated our CI scripts to force an update of pyparsing before running the deploy of the docs.

[goerz]

Turns out it is easy to write the grammar in such a way that it works with a wider range of pyparsing versions (2.0.2 seems like the oldest one that works, but that's more than 6 years old, so that should be plenty)

[hhslepicka]

Great! Thank you for addressing this issue so fast. 👍
doctr-versions-menu is great!

[goerz]

I'll try to make a 0.3.0 release in the next few days. I still have to decide if I want to resolve #6 for that version, or keep it for later.

[goerz]

The 0.3.0 release is out now