CTest runs can take an arbitrarily long time depending on the number and duration of tests configured in a CMake project. Whether one accidentally hit Ctrl+C in the Terminal window or intentionally stopped a CTest run with options like --stop-on-failure, it’s possible to resume from where CTest left off with ctest -F. If CTest ran all tests (whether or not there were failures of tests), then CTest will ignore “-F” and run all tests again or as specified by other CTest command line options.