Bug 1728739 - Fix unicode error on when logging browsertime results on...

                if self.browsertime_failure, and raise an Exception if necessary

                to stop Raptor execution (preventing the results processing).

                """

                match = line_matcher.match(line.decode("utf-8"))

                # NOTE: this hack is to workaround encoding issues on windows

                # a newer version of browsertime adds a `σ` character to output

                line = line.replace(b"\xcf\x83", b"")

                line = line.decode("utf-8")

                match = line_matcher.match(line)

                if not match:

                    LOG.info(line)

                    return