The isolate key has been drafted for quite some time and it seems several users ran into similar user cases:

• tmt should attempt to reinstall test requires before a test run #1862
• Support tagging a test as "destructive" #524
• test.require applies to whole plan #2264

The main idea is to provide a clean environment for each test. This would ensure:

• Only packages required by the test are installed (other tests do not affect guest setup)
• Any changes on the system made by previous tests are discarded

Implementation options:

• Provision a new guest for each test
  • Should work for any provision plugin
  • Easy to implement
  • Can significantly slow down execution
  • Would mean much more resource usage
• Make use of the support for snapshot
  • Could be much faster
  • Would not waste resources
  • Not available for all provision methods
  • Harder to achieve