fix pygments style in docs

[sorcio]

Fixing pygments_style according to readthedocs/sphinx_rtd_theme#633 (comment)

[sorcio]

AppVeyor Python35-x64 Windows build failed (see logs):

pip install codecov
Collecting codecov
  Downloading https://files.pythonhosted.org/packages/8b/28/4c1950a61c3c5786f0f34d643d0d28ec832433c9a7c0bd157690d4eb1d5f/codecov-2.0.15-py2.py3-none-any.whl
Requirement already satisfied: coverage in c:\python35-x64\lib\site-packages (from codecov)
Collecting requests>=2.7.9 (from codecov)
  Could not find a version that satisfies the requirement requests>=2.7.9 (from codecov) (from versions: )
No matching distribution found for requests>=2.7.9 (from codecov)
You are using pip version 9.0.1, however version 10.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

Closing/reopening to see if the problem magically goes away.

[codecov]

Codecov Report

Merging #535 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #535   +/-   ##
=======================================
  Coverage   99.28%   99.28%           
=======================================
  Files          89       89           
  Lines       10483    10483           
  Branches      726      726           
=======================================
  Hits        10408    10408           
  Misses         58       58           
  Partials       17       17

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 82ec7c7...7c0f924. Read the comment docs.

[smurfix]

You could just go to appveyor and click the Rebuild button …

[sorcio]

@smurfix right. If I remember correctly though @njsmith suggested to close/reopen in order to trigger a new build, so the previous build logs are not lost and the issue is documented somewhere. See the link in my comment above, which is still working after the rebuild.

[smurfix]

@sorcio Actually that turns out not to be an issue with Appveyor – they keep the logs of superseded attempts around and assign new build IDs.

I'll ask the Travis people to please do the same thing.

[njsmith]

That appveyor failure makes no sense :-(. If it was on pip 10, and on MacOS, it'd be #508, but in this case I have no idea :-(. Well, I'll add it to #200 anyway...

I also don't understand at all what's going on with RTD and sphinx and pygments and why this patch would fix anything, but I agree that people are claiming that it helped them and it seems harmless otherwise, so I guess let's merge it and see what RTD does.

[njsmith]

I'm looking at trio.readthedocs.io now, and it doesn't look like highlighting is fixed :-(

[sorcio]

Nope :( Maybe we should revert this but I have no idea what I'm doing.

I think the issue is still the missing CSS. _static/pygments.css maybe? It's there but it's not included in the generated HTML document. But it's included unconditionally in the theme (https://github.com/rtfd/sphinx_rtd_theme/blame/master/sphinx_rtd_theme/layout.html#L47) and it's been since 0.3.0. Does that mean RTD is building docs with a very old version of the theme? But Trio explicitly includes the latest theme version (https://github.com/python-trio/trio/blob/master/ci/rtd-requirements.txt) which as of now is 0.3.1 on PyPI.

Other updates to the theme are missing, like alt text on the logo (readthedocs/sphinx_rtd_theme@ed48532#diff-1336f80431f476a232e3c48abb277c51) so I'm pretty sure that we're still using an older theme version. I don't know why yet. I don't have a clear memory of this: did syntax highlighting ever work? I will investigate further later.

[sorcio]

Ah, now I get it. rtd-requirements.txt is installed after RTD installs its requirements. At that stage sphinx-rtd-theme<0.3 is installed, so when it comes to our local requirements an unspecified sphinx-rtd-theme is already satisfied and therefore nothing is installed. We can override this by pinning a more specific version (e.g. >=0.3,<0.4 or ==0.3.1). Or, even better, just ignore it altogether because RTD has already merged the fix that will change the default theme version to <0.4 and it's a matter of days before it gets deployed and our theme will automatically be updated next time we build documentation.

[sorcio]

RTD deployed with the updated theme and now we have syntax highlighting! 🎉

BTW this possibly means that we can do away with some hacks and fixes (but I'm not going to look into that right now)

[njsmith]

Well, I guess it's nice when ignoring a problem makes it go away :-) Thanks for following up!