@Koziolek

I found the cause.

Can you try again after reselecting the language version? (just select the language version again even it says 1.9 already or try resetting)
Your solution is executed using Elixir 1.2 because of https://github.com/Codewars/codewars.com/issues/1909

That's really weird :/
I just reformatted the test code to get the exact line number.
Can you try again and see if the line number in the compile error changes?

Also, can you use the browser's dev tools to see which language version is sent? It might be related to https://github.com/Codewars/codewars.com/issues/1909

@kazk: I get the same kind of ouput with Koziolek's code.

I just tried your solution and couldn't reproduce it.

It's just failing tests like:

Test Failed
Failure
  1) test max_rot (MaxrotTest)
     test/solution_test.exs:15
     
     Maxrot.max_rot(507992495)
     expected: 507992495
     got:      99249557
     
     code: testMaxrot 13, 507992495, 507992495
     stacktrace:
       test/solution_test.exs:28: (test)

Do you see output like this or is it always CompileError? Maybe try resetting (after saving your code somewhere)?

I'm not sure how to_charlist/1 defined in Kernel can be undefined :/
I took a look at the tests, but didn't see anything obvious. I wasn't able to reproduce the error using your solution either.

I also cleaned up the test output so try again and report back if still happens.

Elixir Completions 113

(=> code issue.)

Are you returning the wrong type? Post your code for help.