Version Cygwin

[Anonymouse]

Cygwin is a reserved version[1], alongside Windows and linux and 
the like. However it doesn't seem to be automatically recognised.

> import std.stdio;
> 
> void main()
> {
>     version(Cygwin) writeln("Cygwin");
> }

Compiled from a Cygwin prompt this prints nothing. So I thought 
to add versions: [ "Cygwin" ] to dub.json, but dub refuses.

> Error: version identifier `Cygwin` is reserved and cannot be set

Is there any way to force Cygwin or should I resign to creating 
an alternative lowercase "cygwin" version?

The use-case is to version stdout.flush() here and there to 
counter that the default Cygwin terminal (mintty) doesn't update 
when text is written to the terminal. I forget the reason why it 
doesn't.


[1]: https://dlang.org/spec/version.htm