nim-wiki/Debugging-the-compiler.md

echo renderTree(someNode)  # pretty prints the nimrod ast
debug(someNode)  # outputs some JSON representation
echo typeToString(someType) # pretty prints some type
debug(someType)
echo symbol.name.s
debug(symbol)
echo renderTree(someNode, {renderIds})  # pretty prints the nimrod ast, but annotates symbol IDs
if n.info ?? "temp.nim":  echo renderTree(n)  # only output when it comes from "temp.nim"
if n.info ?? "temp.nim":  writeStackTrace()  # why does it process temp.nim here?