sequtils.nim(934, 11) Error: internal error: environment misses: i`gensym13871022

[xigoi]

Hi, I wrote a simple program for a silly project I'm working on and this weird 
error appeared. Here is the code:
    
    
    import algorithm, sequtils, strutils, tables
    
    proc disorganize(books: seq[string]): seq[string] =
      books.mapIt((b: it, t: it.toCountTable)).sortedByIt((
        it.t['A'] + it.t['a'],
        it.t['E'] + it.t['e'],
        it.t['I'] + it.t['i'],
        it.t['O'] + it.t['o'],
        it.t['U'] + it.t['u'],
        it.b.reversed.join
      )).mapIt(it.b)
    
    stdout.writeLine stdin.readAll.split("\n").disorganize.join("\n")
    
    
    Run