I tried adding "use strict"; to the compiled SJS code, and it turns out that the debug.sjs module uses octal literals, which are not allowed in strict mode. Line 155, in the stylizeWithColor function. The fix is easy: just replace '\033[' with '\u001b['.
On a more general note, I think the output from SJS should always be valid in strict mode (especially since ES6 will have strict mode on by default for ES6 modules). So I would suggest changing the compiler so it detects invalid things (like octal literals) and throws an error.