Time travel to the late 70s and use the lisp machine debugger.
I always felt the drive towards mouse-driven tools in the PARC world (InterLisp/SmallTalk/CedarMesa) was actually a regression because of the loss of history ("how the hell did I get here?")
They also had a proper REPL, and the reason I stay with Java and .NET ecosystems, is because they are the closest we can get back to the Xerox experience, after the UNIX divergence.
Now picture XEmacs and Emacs, running gdb as subprocess, with a little pointed finger showing the current line and a stop sign for breakpoints.
The lower buffer shows the usual gdb repl and output.