Occasionally, one comes across something that turns out to be a bad idea.
Today's edition. Do Not use the hot key sequence for running an expression under the debugger.
I was looking at an object in the Sts Inspector (not sure of the exact class name, doesn't really matter, I don't expect). I wanted to step through the implementation and execution of a particular inherited method. I highlighted the expression, then keyed Ctrl+Shift+G.
The result? A never ending series of empty debugger windows. I interrupted it after some 50 or more were opened. It turns out that Ctrl+Shift has special meaning when opening a debugger.
See the two attached images.