Errors can occur during deployments due to there being different adapters defined in the “development” and the “test” groups in your database.yml file. Your error will differ depending on the adapters you’ve chosen.
For example, if your database.yml file’s “development” group contains:
And it also contains a “test” group with:
This will result in the following slightly obtuse error during your code deployment:
uninitialized constant Mysql2