`yarn run watch` errors with message 'feature' is undefined

[zoubin]

Description

I was trying to build material locally by following the contributing guide.
The setting up process was good, but yarn run watch errored.
Here is the log:

yarn run v1.3.2
$ make -j watch
rm -rf material
/Users/zoubin/Workspace/mt/mkdocs-material/mkdocs-material/node_modules/.bin/webpack --watch
while [ ! -d "./material" ]; do sleep 1; done

Webpack is watching the files…


Looking for Modernizr references

>> 7 matches in src/assets/javascripts/application.js
>> checked, dataset, details, fetch, json, svg, target

>> 1 match in src/assets/stylesheets/extensions/pymdown/_details.scss
>> details

>> 1 match in src/assets/stylesheets/layout/_sidebar.scss
>> csstransforms3d

>> 1 match in src/assets/stylesheets/layout/_nav.scss
>> csstransforms3d

>> Ready to build using these settings:
>> addTest, setClasses
>> Your file will be minified with UglifyJS

Building your customized Modernizr...OK
Hash: 727960a8
Version: webpack 3.8.1
Time: 5536ms
                                          Asset     Size  Chunks                    Chunk Names
                                      main.html  1.16 kB          [emitted]
              assets/images/icons/bitbucket.svg   1.4 kB          [emitted]
                 assets/images/icons/gitlab.svg  1.65 kB          [emitted]
              assets/javascripts/application.js   754 kB       0  [emitted]  [big]  assets/javascripts/application
                assets/javascripts/modernizr.js  27.2 kB       1  [emitted]         assets/javascripts/modernizr
             assets/stylesheets/application.css  87.5 kB       0  [emitted]         assets/javascripts/application
     assets/stylesheets/application-palette.css  44.8 kB       0  [emitted]         assets/javascripts/application
             assets/javascripts/lunr/lunr.da.js  10.3 kB          [emitted]
             assets/javascripts/lunr/lunr.de.js  13.9 kB          [emitted]
             assets/javascripts/lunr/lunr.du.js  15.1 kB          [emitted]
             assets/javascripts/lunr/lunr.es.js  24.4 kB          [emitted]
             assets/javascripts/lunr/lunr.fi.js  20.9 kB          [emitted]
             assets/javascripts/lunr/lunr.fr.js  25.7 kB          [emitted]
             assets/javascripts/lunr/lunr.hu.js  21.3 kB          [emitted]
             assets/javascripts/lunr/lunr.it.js  24.1 kB          [emitted]
             assets/javascripts/lunr/lunr.jp.js  5.05 kB          [emitted]
          assets/javascripts/lunr/lunr.multi.js  3.12 kB          [emitted]
             assets/javascripts/lunr/lunr.no.js  9.95 kB          [emitted]
             assets/javascripts/lunr/lunr.pt.js  22.1 kB          [emitted]
             assets/javascripts/lunr/lunr.ro.js  23.2 kB          [emitted]
             assets/javascripts/lunr/lunr.ru.js  19.1 kB          [emitted]
assets/javascripts/lunr/lunr.stemmer.support.js  13.5 kB          [emitted]
             assets/javascripts/lunr/lunr.sv.js  9.63 kB          [emitted]
             assets/javascripts/lunr/lunr.tr.js  38.3 kB          [emitted]
             assets/javascripts/lunr/tinyseg.js  22.9 kB          [emitted]
                      assets/images/favicon.ico  1.15 kB          [emitted]
                      assets/images/favicon.png  1.06 kB          [emitted]
                                    __init__.py  0 bytes          [emitted]
                               mkdocs_theme.yml  2.62 kB          [emitted]
                                       404.html  1.25 kB          [emitted]
                                      base.html    12 kB          [emitted]
                 assets/images/icons/github.svg  1.18 kB          [emitted]
                           partials/footer.html  3.87 kB          [emitted]
                           partials/header.html  3.43 kB          [emitted]
                             partials/hero.html  1.44 kB          [emitted]
           partials/integrations/analytics.html  2.38 kB          [emitted]
              partials/integrations/disqus.html  1.62 kB          [emitted]
                         partials/language.html  1.56 kB          [emitted]
                      partials/language/da.html  1.82 kB          [emitted]
                      partials/language/de.html  1.84 kB          [emitted]
                      partials/language/en.html  1.82 kB          [emitted]
                      partials/language/es.html  1.87 kB          [emitted]
                      partials/language/fr.html  1.87 kB          [emitted]
                      partials/language/it.html  1.79 kB          [emitted]
                      partials/language/ja.html  1.89 kB          [emitted]
                      partials/language/kr.html  1.88 kB          [emitted]
                      partials/language/nl.html  1.86 kB          [emitted]
                      partials/language/no.html  1.81 kB          [emitted]
                      partials/language/pl.html  1.88 kB          [emitted]
                      partials/language/pt.html  1.88 kB          [emitted]
                      partials/language/ru.html  2.04 kB          [emitted]
                      partials/language/sv.html  1.82 kB          [emitted]
                 partials/language/zh-Hant.html  1.85 kB          [emitted]
                      partials/language/zh.html  1.84 kB          [emitted]
                         partials/nav-item.html  3.71 kB          [emitted]
                              partials/nav.html  2.05 kB          [emitted]
                           partials/search.html  2.27 kB          [emitted]
                           partials/social.html  1.59 kB          [emitted]
                           partials/source.html  2.18 kB          [emitted]
                        partials/tabs-item.html  2.49 kB          [emitted]
                             partials/tabs.html  1.58 kB          [emitted]
                         partials/toc-item.html   1.6 kB          [emitted]
                              partials/toc.html  2.72 kB          [emitted]
   [0] ./src/assets/javascripts/providers/jsx.js 3.04 kB {0} [built]
   [2] (webpack)/buildin/global.js 488 bytes {0} [built]
   [4] ./src/assets/javascripts/modernizr.js 53 bytes {1} [built]
   [5] ./.modernizr-autorc 7.29 kB {1} [built]
   [6] ./src/assets/javascripts/application.js 18.1 kB {0} [built]
   [7] ./src/assets/images/icons/bitbucket.svg 79 bytes {0} [built]
   [8] ./src/assets/images/icons/github.svg 76 bytes {0} [built]
   [9] ./src/assets/images/icons/gitlab.svg 76 bytes {0} [built]
  [10] ./src/assets/stylesheets/application.scss 41 bytes {0} [built]
  [11] ./src/assets/stylesheets/application-palette.scss 41 bytes {0} [built]
    + 44 hidden modules
Child extract-text-webpack-plugin node_modules/extract-text-webpack-plugin/dist node_modules/css-loader/index.js??ref--3-1!node_modules/postcss-loader/lib/index.js??postcss!node_modules/sass-loader/lib/loader.js??ref--3-3!src/assets/stylesheets/application.scss:
       [0] ./node_modules/css-loader?{}!./node_modules/postcss-loader/lib?{"ident":"postcss","plugins":[null,null]}!./node_modules/sass-loader/lib/loader.js?{"includePaths":["node_modules/modularscale-sass/stylesheets","node_modules/material-design-color","node_modules/material-shadows"]}!./src/assets/stylesheets/application.scss 90.1 kB {0} [built]
        + 1 hidden module
Child extract-text-webpack-plugin node_modules/extract-text-webpack-plugin/dist node_modules/css-loader/index.js??ref--4-1!node_modules/postcss-loader/lib/index.js??postcss!node_modules/sass-loader/lib/loader.js??ref--4-3!src/assets/stylesheets/application-palette.scss:
       [0] ./node_modules/css-loader?{}!./node_modules/postcss-loader/lib?{"ident":"postcss","plugins":[null,null]}!./node_modules/sass-loader/lib/loader.js?{"includePaths":["node_modules/modularscale-sass/stylesheets","node_modules/material-design-color","node_modules/material-shadows"]}!./src/assets/stylesheets/application-palette.scss 47 kB {0} [built]
        + 1 hidden module
mkdocs serve
INFO    -  Building documentation...
INFO    -  Cleaning site directory
ERROR   -  Error building page extensions/metadata.md
Traceback (most recent call last):
  File "/usr/local/bin/mkdocs", line 11, in <module>
    sys.exit(cli())
  File "/usr/local/lib/python2.7/site-packages/click/core.py", line 664, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/click/core.py", line 644, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python2.7/site-packages/click/core.py", line 991, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python2.7/site-packages/click/core.py", line 837, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python2.7/site-packages/click/core.py", line 464, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python2.7/site-packages/mkdocs/__main__.py", line 127, in serve_command
    livereload=livereload
  File "/usr/local/lib/python2.7/site-packages/mkdocs/commands/serve.py", line 117, in serve
    config = builder()
  File "/usr/local/lib/python2.7/site-packages/mkdocs/commands/serve.py", line 112, in builder
    build(config, live_server=live_server, dirty=dirty)
  File "/usr/local/lib/python2.7/site-packages/mkdocs/commands/build.py", line 282, in build
    build_pages(config, dirty=dirty)
  File "/usr/local/lib/python2.7/site-packages/mkdocs/commands/build.py", line 242, in build_pages
    _build_page(page, config, site_navigation, env)
  File "/usr/local/lib/python2.7/site-packages/mkdocs/commands/build.py", line 158, in _build_page
    output_content = template.render(context)
  File "/usr/local/lib/python2.7/site-packages/jinja2/environment.py", line 969, in render
    return self.environment.handle_exception(exc_info, True)
  File "/usr/local/lib/python2.7/site-packages/jinja2/environment.py", line 742, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/Users/zoubin/Workspace/mt/mkdocs-material/mkdocs-material/material/main.html", line 1, in top-level template code
    {% extends "base.html" %}
  File "/Users/zoubin/Workspace/mt/mkdocs-material/mkdocs-material/material/base.html", line 104, in top-level template code
    {% block hero %}
  File "/Users/zoubin/Workspace/mt/mkdocs-material/mkdocs-material/material/base.html", line 106, in block "hero"
    {% include "partials/hero.html" with context %}
  File "/Users/zoubin/Workspace/mt/mkdocs-material/mkdocs-material/material/partials/hero.html", line 2, in top-level template code
    {% if not feature.tabs %}
  File "/usr/local/lib/python2.7/site-packages/jinja2/environment.py", line 397, in getattr
    return getattr(obj, attribute)
jinja2.exceptions.UndefinedError: 'feature' is undefined
make: *** [watch-mkdocs] Error 1
make: *** Waiting for unfinished jobs....

Expected behavior

[What you expected to happen]

Actual behavior

[What is actually happening]

Steps to reproduce the bug

1. [First step]
2. [Second step]
3. [and so on...]

Package versions

• Python: 2.7.8
• MkDocs: 0.17.2
• Material: a7da5d5

Project configuration

The contents of your mkdocs.yml

System information

• OS: macOS 10.13.2 Beta 17C67b
• Browser: [The browser used, if relevant]

[squidfunk]

Hmm that's strange as I cannot reproduce it. Which version of Jinja do you have installed?

pip show jinja2

On my machine this prints:

Name: Jinja2
Version: 2.10
Summary: A small but fast and easy to use stand-alone template engine written in pure python.
Home-page: http://jinja.pocoo.org/
Author: Armin Ronacher
Author-email: armin.ronacher@active-4.com
License: BSD
Location: /Users/squidfunk/Library/Python/2.7/lib/python/site-packages
Requires: MarkupSafe

[squidfunk]

Hmm that's strange as I cannot reproduce it. Which version of Jinja do you have installed?

pip show jinja2

On my machine this prints:

Name: Jinja2
Version: 2.10
Summary: A small but fast and easy to use stand-alone template engine written in pure python.
Home-page: http://jinja.pocoo.org/
Author: Armin Ronacher
Author-email: armin.ronacher@active-4.com
License: BSD
Location: /Users/squidfunk/Library/Python/2.7/lib/python/site-packages
Requires: MarkupSafe

[zoubin]

Sorry for the delay.
On my mac,

pip show jinja2

prints:

Name: Jinja2
Version: 2.7.3
Summary: A small but fast and easy to use stand-alone template engine written in pure python.
Home-page: http://jinja.pocoo.org/
Author: Armin Ronacher
Author-email: armin.ronacher@active-4.com
License: BSD
Location: /usr/local/lib/python2.7/site-packages
Requires: markupsafe

[zoubin]

Sorry for the delay.
On my mac,

pip show jinja2

prints:

Name: Jinja2
Version: 2.7.3
Summary: A small but fast and easy to use stand-alone template engine written in pure python.
Home-page: http://jinja.pocoo.org/
Author: Armin Ronacher
Author-email: armin.ronacher@active-4.com
License: BSD
Location: /usr/local/lib/python2.7/site-packages
Requires: markupsafe

[squidfunk]

This is a little regression that is incompatible with Jinja 2.7, as Jinja changed the behavior of imports and contexts in 2.9. Upgrading it to >2.9 will fix the issue, but I will also provide a fix shortly.

[squidfunk]

This is a little regression that is incompatible with Jinja 2.7, as Jinja changed the behavior of imports and contexts in 2.9. Upgrading it to >2.9 will fix the issue, but I will also provide a fix shortly.

[squidfunk]

Fixed in master and released as 2.2.4

[squidfunk]

Fixed in master and released as 2.2.4