Unlike the JUnit reporter, the TeamCity reporter does not include the location of failure. It includes only the location of the test (i.e. its first line):

##teamcity[testFailed name='Test group Second test' message='tests.go:33' details='Unexpected error:|n    <*errors.errorString || 0xc0001b8000>: {|n        s: "failed on purpose",|n    }|n    failed on purpose|noccurred|n']

When reviewing a failed test in TeamCity, it's helpful to know the location of the failure.