🐛 FIX: fix undefined sphinx var "meta" in jinja

[drammock]

closes #394

As far as I can tell, the site still renders fine after this change, but I would welcome a second pair of eyes.

[choldgraf]

Hmmm - I think the question is what happened to meta - did it get deprecated in jinja or something?

[drammock]

I didn't see anything about it in the changelog...

[larsoner]

We are on a prerelease RC1 (and before that alpha):

https://pypi.org/project/Jinja2/#history

Might be worth looking through their issue tracker and opening an issue that either this is a BUG or a DOC problem at their end

[jorisvandenbossche]

@drammock is there a full log of the doc build where you are seeing the error? (#394 only has the actual error)

It might be that meta is not defined for some special pages like genindex (that's the page where it is failing with this error in sphinx-themes/sphinx-themes.org#70)

[choldgraf]

Good point @jorisvandenbossche - I bet that you're right. As along as we are confident that we won't miss config elsewhere, then I'm +1 on this. I suppose that if we didn't pass crucial config in other places as a result of removing this, then it'd show up as errors elsewhere in the test suite

[drammock]

@jorisvandenbossche here is the full traceback on our CI: https://app.circleci.com/pipelines/github/mne-tools/mne-python/7914/workflows/246aeec9-b376-484a-af05-81bd0b815be3/jobs/27512#step-139-1859

[jorisvandenbossche]

Thanks, so there it also errored for the genindex page.

I am not sure why it hits us now and not before, but in any case what this PR does (is undefined check) is also how eg rtd theme is doing it: https://github.com/readthedocs/sphinx_rtd_theme/blob/9df65f15c5f62ac5a847c505f559c00586316936/sphinx_rtd_theme/breadcrumbs.html#L1

[choldgraf]

then I say let's

[bollwyvl]

Two things:

• can we add a test?
• should we add a canary excursion with pip install --pre to catch some of these things sooner?
  • or perhaps more targetd just our runtime dependencies?

[pradyunsg]

FWIW, meta comes from Sphinx (see https://www.sphinx-doc.org/en/master/templating.html#meta).

As noted already, it can be undefined for some pages, which is why things are failing for sphinx-themes.org. :)

[choldgraf]

I guess that the test for this should entail building a sphinx site with a genindex (or some other page without a meta tag) and making sure it doesn't error. Does this not already happen in our test suite?

@drammock what do you think?

[jorisvandenbossche]

I suppose the demo docs / tests already do that, but we need an environment with the dev versions of sphinx/jinja to catch this

[choldgraf]

Ah - so perhaps we need to add another matrix dimension here for Sphinx version?

https://github.com/pydata/pydata-sphinx-theme/blob/master/.github/workflows/tests.yml#L65

Reasonable to strive to keep up with the latest 2 major versions in general + the pre-release (so, 2.x, 3.x, 4.xa)?

[jorisvandenbossche]

Ah - so perhaps we need to add another matrix dimension here for Sphinx version?

Yes, it might indeed be good to test against multiple versions of sphinx.
For now, short term, I quickly added a build that simply installs any pre-release version if available of sphinx and jinja2 (it's actually jinja2 that is causing the error here, not sphinx) -> #402

[jorisvandenbossche]

So CI was failing in #402, and passing now with the fix in this PR. So merging.

Thanks @drammock !

[jorisvandenbossche]

I also made a 0.6.2 release with this fix (https://github.com/pydata/pydata-sphinx-theme/releases/tag/v0.6.2)

[choldgraf]

Woooo! Thanks @drammock for fixing this!

[jorisvandenbossche]

(BTW, Chris, there is still something very strange with your git ;) For the previous 0.6.1 release, the release commit (f54466a) was this time done 3 days in the past .. For the 0.6.0 release you "only" did it one day in the past ;))