is this a bug with writeln / std.algorithm.remove?

[arturg]

On Friday, 16 February 2018 at 13:28:59 UTC, Steven Schveighoffer 
wrote:
>
> Strictly speaking, this is not necessarily proof that it's in 
> phobos, there could have been changes elsewhere that cause one 
> of the conditions to fail.
>
> However, testing this out, I found something very weird.
>
> If you pragma(msg, isInputRange!(typeof(dgs))); inside your 
> file, then it compiles (and prints true for that pragma).
>
> Makes no sense at all. Definitely seems like a compiler bug. A 
> pragma(msg) shouldn't affect the outcome.
>
> -Steve

ok so what should the bug report look like?