Find Where a Rake Task is Defined

You can use rake --where task to find the source location that defines task:

bundle exec rake --where assets:precompile
rake assets:precompile              /home/henning/.rbenv/versions/2.6.6/lib/ruby/gems/2.6.0/gems/precompiled_assets-0.2.1/lib/precompiled_assets/tasks/assets.rake:5:in `block in <main>'