Hi, When I want to run the coverage of for example Zincâs Client and Server tests, it will either hang (in the case of Zincâs test cases) or fail because the coverage uses BlockClosure>>valueUnpreemptively for running the tests. The relevant method is TestRunner>>collectCoverageFor:. So when a test is run, it is not able to be preempted by another process, like for example a local server which is needed to run the actual test in Zincâs case. When I use BlockClosure>>valueUninterruptably it works. Can someone tell me if it is wrong to use that instead? Is valueUnpreemptively necessary in this case, and if so, why? To reproduce: Load fresh image, select Zinc's ZnClientTests and ZnServerTests, click on âRun Coverageâ -> hanging image. Thanks, Skip