public string SummarizeErrors()

Convenience method for summarizing errors (or exceptions) that occurred during a build into a single line of text. If no error was logged this returns an empty string. If a single error was logged this reports the error messages. Otherwise it reports the number of errors, for example "5 errors".

Note: To examine all errors, warnings and other messages recorded during a build you can enumerating through the build _steps and check _messages. And to retrieve the count of errors call _totalErrors.