Which environment variable must be configured to make Terraform's logging more verbose?

To enhance Terraform's logging verbosity, configuring the environment variable TF_LOG is essential. When set, this variable allows you to control the level of logging output generated by Terraform, providing insights into its operations and potentially aiding in troubleshooting. The TF_LOG variable can take values such as TRACE, DEBUG, INFO, WARN, or ERROR, with TRACE being the most verbose. This granular output assists users in understanding what Terraform is doing under the hood, which can be particularly valuable during debugging sessions or when assessing the behavior of the tool.

TF_VAR is utilized for setting variables in Terraform configurations at runtime, and does not influence logging behavior. TF_DEBUG is not recognized as a specific integer variable for Terraform; it is mainly a concept in other debugging tools. TF_STATE pertains to managing and referencing Terraform's state file, and does not impact verbosity or logging levels. Thus, only TF_LOG correctly fulfills the requirement for adjusting Terraform's logging verbosity.