godartsass returns "unexpected EOF"

Question

I am attempting to compile indented sass to css using Go's github.com/bep/godartsass/v2 package; however, I receive the error unexpected EOF no matter the sass input.

var sassTranspiler *godartsass.Transpiler

func compileSass() {
    var err error
    dir := "www/assets"

    sassTranspiler, err = godartsass.Start(godartsass.Options{})
    if err != nil {
        log.Fatal(err)
    }
    defer sassTranspiler.Close()

    err = filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
        if err != nil {
            return err
        }

        if strings.HasSuffix(info.Name(), ".sass") {
            _, err = sassTranspiler.Execute(godartsass.Args{
                Source:          path,
                OutputStyle:     godartsass.OutputStyleCompressed,
                SourceSyntax:    godartsass.SourceSyntaxSASS,
                EnableSourceMap: true,
            })
            if err != nil {
                log.Fatal(err)
            }

            ...
        }

        return nil
    })

    if err != nil {
        log.Fatal(err)
    }
}