未定义：Windows上的syscall.Kill

I'm using eaburns/Watch library on a windows machine, but when trying to get the package with go get github.com/eaburns/Watch I get the following errors:

main.go:159: undefined: syscall.Kill
main.go:169: undefined: syscall.Wait4
main.go:169: undefined: syscall.WNOHANG

Any reason why this happens only on windows computers? Does anybody knows how to fix this?

Thanks in advanced