Compile in support for Low Level TRACE-ing of the main interpreter loop.
-When this preprocessor symbol is defined, before PyEval_EvalFrame (eval_frame in
-2.3 and 2.2, eval_code2 before that) executes a frame's code it checks the
-frame's global namespace for a variable "__lltrace__". If such a variable is
-found, mounds of information about what the interpreter is doing are sprayed to
-stdout, such as every opcode and opcode argument and values pushed onto and
-popped off the value stack.
+When this preprocessor symbol is defined, before PyEval_EvalFrame executes a
+frame's code it checks the frame's global namespace for a variable
+"__lltrace__". If such a variable is found, mounds of information about what
+the interpreter is doing are sprayed to stdout, such as every opcode and opcode
+argument and values pushed onto and popped off the value stack.
Not useful very often, but very useful when needed.