i use gulp-postcss and postcss-cssnext to translate css，and got problems

i use cssnext to write my css

:root{
    --ellipsis: {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    };
};

and use @apply --ellipsis in 3 places

.div1{
    @apply --ellipsis
}
.div2{
    @apply --ellipsis
}
.div3{
    @apply --ellipsis
}

and i use gulp and postcss-cssnext

gulp.task('postcss',function(){
    return gulp.src('src/css/*.css')
        .pipe(plumber())
        .pipe(postcss([
            cssnext({
                browsers: ['last 2 versions', 'Android >= 4.0'],
                features: {
                    rem: false
                }
            })
        ]))
        .pipe(gulp.dest('dist/css'))
});

but only the first place is useful，

.div1{
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap; 
}
.div2{
}
.div3{
}

i have to write like this:

:root{
    --ellipsis: {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    };
};
.div1{
    @apply --ellipsis
}
:root{
    --ellipsis: {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    };
};
.div2{
    @apply --ellipsis
}
:root{
    --ellipsis: {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    };
};
.div3{
    @apply --ellipsis
}

but this must not be written like that,there must be something wrong...

"devDependencies": {
    "autoprefixer": "^7.1.1",
    "gulp": "^3.9.1",
    "gulp-plumber": "^1.1.0",
    "gulp-postcss": "^7.0.0",
    "postcss-cssnext": "^2.11.0",
}

who can save me....

oh...I fixed it myself....

I feel that is not my fault but the problem of gulp-postcss,it is the newest version,so I install an old one 6.4.0,and it worked...