First Failure

For some test failures TeamCity can show "First Failure" build.

This is the build where TeamCity detected the first failure of this test for the same Build Configuration. I.e. starting from the current build, TeamCity goes back through the build history to find out when this test failed the first time. Builds without this test are skipped, if successful test run was found, searching stops.

"Back through the history" means that builds are analyzed with regard of changes as they are detected by TeamCity, i.e. History Builds will be processed correctly.

Tests are considered the same when they have the same name. If there are several tests with the same name within the build, TeamCity counts order number of the test with the same name and considers it as well.