how to debug a twig template?

[22:46] chx: andypost: testing , make sure that the cache key is set to a directory so you can look at a generated php file
[22:46] chx: so, in twig.engine
[22:46] chx: 'cache' => DRUPAL_ROOT . '/compilation_cache',
[22:46] chx: 'cache' => FALSE,
[22:47] chx: remove the cache FALSE row
[22:47] chx: and then check the generated php in the compilation cache dir
[22:47] chx: that's how you can debug if there's a problem

This patch enables cache, so it possible to debug compiled taemplates

No reason to change 'cache' => FALSE

updating title.

You *test* the template by putting it in the stark theme, and then flushing your site's caches. Then look at the source code.