Support compiling the same source to multiple destinations

I'm using Dart Sass 1.22.12.

I'm trying to compile the same sass to multiple directories while watching them.

I have the following in my script: sass --watch sass:sv/css sass:hv/css

But it throws this error: Duplicate source "sass".

I've also tried replacing the path sass with sass/site.scss, but then it just says Duplicate source "sass/site.scss". instead.

Both paths appear to work just fine when I compile them individually, so I don't think there's something wrong with the paths it needs to be compiled to.

Is there something wrong with my script by any chance? Or is it simply not possible to compile to multiple directories with the same input?