Cannot escape vertical bar ('|') in file paths

[stomah]

ninja 1.12.1

rule touch
  command = touch $out
build a$|b: touch

ninja: error: build.ninja:3: bad $-escape (literal $ must be written as $$)
build a$|b: touch
       ^ near here

If unescaped, ninja interprets it as an implicit output.

There should also probably be a way to include any bytes in file paths (even newlines, other control characters and invalid UTF-8).