Sometime it happens that you want to run server with pending migrations.
For example you run rake db:rollback
now will have one pending migration and you want to see the effect of that migration and for this you need to run the server. Now if you will try to run server it will give you the error:
Migrations are pending. To resolve this issue, run: bin/rake db:migrate RAILS_ENV=development
so, to get rid of this error you can comment a following line from specific environment file:
# config.active_record.migration_error = :page_load
It raise an error on page load if there are pending migrations.