Variable scope issue in loops

[LeighBicknell]

Example:

$Base:1.618;
$Exponent:4;

$Rtn: $Base;

@for $i from 1 to $Exponent
{
    $Rtn: $Rtn * $Base;
    $DeclaredInLoop: $Rtn;
    #supertest2{test:$Rtn;}
}
#supertest3{test:$Rtn;DeclaredInLoop:$DeclaredInLoop;}

This outputs

#supertest2{test:2.618}
#supertest2{test:4.326}
#supertest2{test:6.854}
#supertest2{test:11.089}
#supertest3{test:1.618;DeclaredInLoop:false;}

You can see that after it exits the loop $Rtn has returned to it's original value, instead of maintaining the value it has by the end of the loop (11.089). And the $DeclaredInLoop variable simply returns false outside of the loop.