Jekyll post not generated

I am trying to add a new post to my Jekyll site, but I cannot see it on the generated pages when I run jekyll serve.

What are some common reasons for a Jekyll post to not be generated?

• The post is not placed in the _posts directory.
• The post has incorrect title. Posts should be named YEAR-MONTH-DAY-title.MARKUP (Note the MARKUP extension, which is usually .md or .markdown)
• The post's date is in the future. You can make the post visible by setting future: true in _config.yml (documentation)
• The post has published: false in its front matter. Set it to true.
• The title contains a : character. Replace it with &#58. Works in jekyll 3.8.3 (and probably in other 'recent' releases).

You can use jekyll build --verbose to view build process in detail.

Exmaple output:

  Logging at level: debug
Configuration file: /home/fangxing/fffx.github.io/_config.yml
  Logging at level: debug
         Requiring: jekyll-archives
         Requiring: jekyll-livereload
         Requiring: kramdown
            Source: /home/fangxing/fffx.github.io
       Destination: /home/fangxing/fffx.github.io/_site
 Incremental build: enabled
      Generating... 
       EntryFilter: excluded /Gemfile
       EntryFilter: excluded /Gemfile.lock
           Reading: _posts/2018-01-14-new-post.md
           Reading: _posts/2014-01-01-example-content.md
           Reading: _posts/2014-01-02-introducing-lanyon.md
           Reading: _posts/2017-11-21-welcome-to-jekyll.markdown
           Reading: _posts/2018-01-14-boot-android-on-charge.md
           Reading: _posts/2013-12-31-whats-jekyll.md
          Skipping: _posts/2018-01-14-boot-android-on-charge.md has a future date
        Generating: Jekyll::Archives::Archives finished in 0.000122873 seconds.
        Generating: JekyllFeed::Generator finished in 0.000468846 seconds.
        ...

from the log I found jeklly skipped 2018-01-14-boot-android-on-charge.md because it has a future date.

One possible reason is that the date specified in the front matter does not contain a time zone offset, in which case it defaults to UTC, not the time zone of the local machine as you might expect. I wasted an hour on this until UTC "caught up" with my current local time zone, BST.

I haven't found a definitive answer to this but I think the date in the front matter must be given in UTC with a timezone offset (which defaults to zero if omitted).

So date: 2018-05-03 12:34:27 is in UTC irrespective of where in the world you are, and irrespective of the timezone setting in _config.yml.

So be careful to specify datetimes like this:

date: 2018-05-03 12:34:27 +0100

Or it can be browser cache as well if you are looking not in the _site folder but directly on the blog's main page with the list of posts.

I have written Rspec tests for my blog that express these rules:

require 'spec_helper'
require 'yaml'

# Documented at https://jekyllrb.com/news/2017/03/02/jekyll-3-4-1-released/
post_regex = %r!^(?:.+/)*(\d{2,4}-\d{1,2}-\d{1,2})-(.*)(\.[^.]+)$!

def date_in_front_matter(date)
  return date if date.is_a?(Date)
  return date.to_date if date.is_a?(Time)
  return Date.parse(date) if date.is_a?(String)
end

describe 'posts' do
  Dir.glob("_posts/*md").each do |file|
    basename = File.basename(file)

    context basename do
      front_matter = YAML.load(File.read(file).split(/---/)[1])

      it 'filename must match documented post regex' do
        expect(basename).to match post_regex
      end

      it 'date in file name same day as date in front matter' do
        date_in_file_name = Date.parse(post_regex.match(basename).captures[0])
        expect(date_in_front_matter(front_matter['date'])).to eq date_in_file_name
      end

      it 'title in front matter should not contain a colon' do
        expect(front_matter['title']).to_not match /:/
      end

      it 'front matter should not have published: false' do
        expect(front_matter['published']).to_not be false
      end
    end
  end
end

This may be of use to others as I was losing a lot of time due to typos in the date etc.

These tests along with the rest of the Rspec config can be seen in context here.

Just to add one more reason, when you move an article from _drafts to _post, you sometimes need to delete the _site for the article to be regenerated.

In my case it often happens that _site will not be entirely deleted before re-generation so the new article won't appear.

Anyway rm -rf _site and bundle exec jekyll serve works :)

If you are unable to track the file in --verbose and if the file is silently ignored then try removing collections_dir in the config.yml file. That solved the issue for me.

My post also did not appear an the error was, that in my name I used a dot, e.g. 2017-10-18-test.2.md.
This is not accepted, you have to use 2017-10-18-test2.md.

If you have checked your front matter, and all seems well, and even jekyll build --verbose doesn't reveal anything (in my case, it just acted as if the file didn't exist at all, not even listing it as excluded), check the encoding of your file. Apparently, it needs to be UTF-8 without signature. It it's UTF-8 BOM (or UTF-8 with Signature as some text editors call it), then it will be silently ignored. To make matters worse, some editors will display both types as just UTF-8, making the difference even harder to spot.