Rake: --dry-run, --trace, and -T

When using rake it can often be useful to know the order in which tasks are being executed. To list the execution order you can issue the following command.

rake --dry-run

The --dry-run option works well; however, it does not report tasks that are explicitly invoked.

Rake::Task["test:units"].invoke

The above code can be used to explicitly invoke a task (test:units in the example). Rails uses this in various database and testing tasks. However, it's still possible to see which tasks are being executed. The following code will show each task as it's executed.

rake --trace

The --trace option provides a lot of information, but if you have grep available it can be trimmed down easily.

rake --trace | grep Execute

Also, when running rake with the -T option you can also pass another parameter to list only the commands that contain that parameter. For example, the following code returns all the tasks that contain 'db' in their description.

rake -T db