feature request: call debugger when test fails

[HDembinski]

It would be a handy time-saver if one could call b2 with an option that automatically runs the first "run" test that fails in the debugger.

[stale[bot]]

Thank you for your contributions. Main development of B2 has moved to https://github.com/bfgroup/b2 This issue has been automatically marked as "transition" to indicate the potential for needing transition to the new B2 development project.