When you are working with ctx, the error log can be useful to help you check the variables or solve a bug.
In bottom of Clara.io UI, we provide “Log“ window to display the logs, and there are three separated log types, “Errors“, “Warnings“ and “Logs“.
In your script, you can use log.error(), log.warning(), log.info() to print logs .
For Example:
log.error("You got an error in Line 222!");
log.warning("'A' is greater than 10!");
log.info("Create a Box");