The unit tests are run on the releng ci instance.
The table shows the unit test results for this build on the platforms tested. You may access the test results page specific to each component on a specific platform by clicking the cell link. Normally, the number of errors is indicated in the cell.
A negative number or "DNF" means the test "Did Not Finish" for unknown reasons and hence no results page is available. In that case, more information can sometimes be found in the console logs.