What is wrong with task gulp jade and how to include css content in jade?

Question

css

Something I again got confused in the galpa%) There is a task.

// jade task
gulp.task('jade', function() {
    gulp.src('asset/jade/**/*.jade','!asset/jade/**/_*.jade')
    .pipe(plumber())
    .pipe(jade({
        pretty: '\t'
    }))
    .pipe(gulp.dest('./'))
});

Gives an error on startup.

TypeError: Cannot assign to read only property 'cwd' of !asset/jade/**/_*.jade

There are 2 files in the jade folder.
--- _head.jade
---index.jade
The index.jade is written include _head.jade
I don't understand something and do I need some other plugin?
And another related question.
I want to pour css directly into the file into the index.html output file.
Can this be done with jade?

Answer 1

1. The *.jade files need to be renamed to *.pug
2. Edit gulpfile.js:

gulp.src(['asset/jade/**/*.pug','!asset/jade/**/_*.pug'])