The Backtrace tab displays the function calls on the execution stack in the code being stepped.
The topmost item in the backtrace area shows the next step, known as the status. When calling a function, the status item contains the arguments and when returning from any form, the status item contains its return values. You can see the contents of the status item by expanding it. You can make the status item expand automatically if you wish, as described in Backtrace preferences.
The second topmost item in the backtrace area is the active frame. This shows the function executing when the breakpoint was reached, and its arguments.
For function calls, arguments and local variables can be seen by expanding the item. You can make the active frame expand automatically if you wish, as described in Backtrace preferences. Just as in the Backtrace area of the Debugger tool, these stack frames and variables can be operated on using the Debug > Frame and Debug > Variables menus. For details, see Backtrace area.