Need for New Diagnostic Tool

• Must use bisection to reduce number of commits to be run

• Need to focus on differences in test output rather than test result

  • Has output of lib/locale.t at commit N changed from commit N - 1?

  • "First FAIL" not sufficient

  • We know lib/locale.t failed in at least 2 different ways

• Need to identify each commit at which test output changed

  • After we identify first change in test output, must repeatedly bisect