Exclude

Here is the default value for Jekyll 3:

exclude:
  - vendor/
  - Gemfile
  - Gemfile.lock
  - node_modules/

The vendor folder is actually ignored as "vendor/bundle/", "vendor/cache/", "vendor/gems/", "vendor/ruby/".

When you override exclude, you must also include those base values. Note that in Jekyll 4 that is not the case.

Using system and custom values.

exclude:
  - docs/
  - vendor/
  - Gemfile
  - LICENSE
  - Makefile
  - README.md
  - sample*.png

Note that if you ignore LICENSE and Gemfile, then LICENSE-source and Gemfile.lock also get ignored.

You may use a globstar pattern. Make sure to use quotes if you pattern starts or ends with an asterisk.

exclude:
  - "*.png"

However, using /*.png doesn’t work as expected, as images are removed at all levels such as in assets/.

Therefore rather ignore explicitly:

exclude:
  - sample.png

Or:

exclude:
  - sample*.png