Sorry, what I meant was the TraceBack. It helped a great deal when learning programming and hunt those nasty bugs:

  Traceback (most recent call last):
    File "C:/Users/wuschel/Desktop/error-track.py", line 3,   in <module>
      newstrin = teststrin + 3
  TypeError: cannot concatenate 'str' and 'int' objects

In clojure, you get those error reports in java lingo - I don't know how fast you can get use to that kind of error messages when you do not know Java. Now, this one is obvious, but it just should serve as an example:

  clojure.lang.Compiler$CompilerException: 
  java.lang.RuntimeException: clojure.lang.Compiler$CompilerException: java.lang.RuntimeException: Unable to resolve symbol: b in this context, compiling:(null:4:1)