Respecting the Stream API of raises and allowed tags (`raises: [Defect, IOError, OSError], tags: [WriteIOEffect]`) gives a better error message :
`/usercode/in.nim(14, 114) template/generic instantiation from here` `/usercode/in.nim(16, 15) Error: allocChunk(s.al) can have an unlisted effect: RootEffect` Searching for RootEffect in the docs : <https://nim-lang.org/docs/system.html#RootEffect> => this is caused by allocChunk being a method : <https://play.nim-lang.org/#pasty=EOTBGpPN>
