gulp(v4)で、pugがコンパイルされない

閲覧ありがとうございます。
gulp(v4)で、pugをhtmlにコンパイルしたいのですが、上手くいきません。
お手数ですが、解決法をお教えただけますと幸いです。
よろしくお願い致します。

▼構造

▼行ったコマンド
C:\Users\Hina\Desktop\sample にて、

npm install gulp --save-dev
npm init -y
npm install gulp-sass --save-dev
npm install gulp-autoprefixer --save-dev
npm install gulp-sourcemaps --save-dev
npm run dev

npm install browser-sync --save-dev
npx gulp

npm install gulp-pug --save-dev
npm run dev

▼エラー文
(pugファイルにて、上書き保存を行うと出ます。それまでは、
[16:07:35] Using gulpfile ~\Desktop\sample\gulpfile.js
[16:07:35] Starting 'dev'...
で止まっています。）

PS C:\Users\Hina\Desktop\sample> npm run dev

> sample@1.0.0 dev C:\Users\Hina\Desktop\sample
> gulp dev

[16:07:35] Using gulpfile ~\Desktop\sample\gulpfile.js
[16:07:35] Starting 'dev'...
[16:07:57] Starting 'pug'...
[16:07:57] 'pug' errored after 38 ms
[16:07:57] ReferenceError: plumber is not defined
    at gulp.task.done (C:\Users\Hina\Desktop\sample\gulpfile.js:66:5)
    at taskWrapper (C:\Users\Hina\node_modules\undertaker\lib\set-task.js:13:15)
    at bound (domain.js:395:14)
    at runBound (domain.js:408:12)
    at asyncRunner (C:\Users\Hina\node_modules\async-done\index.js:55:18)
    at process._tickCallback (internal/process/next_tick.js:61:11)

▼index.pug

pug
1doctype html
2html(lang="ja")
3  head
4    meta(charset="utf-8")
5    style(src="css/style.css")
6    title Pugテスト
7  body
8    h1.sitettl Pugテストサイトタイトル
9    main.main
10      h2.content_ttl メインタイトル

▼gulpfile.js

JavaScript
1const gulp = require('gulp');
2const autoprefixer = require('gulp-autoprefixer');
3const sass = require('gulp-sass');
4const sourcemaps = require('gulp-sourcemaps');
5
6const paths = {
7  'src': {
8    'scss': 'src/scss/**/*.scss',
9      pug: "src/pug/**/*.pug",
10  },
11  'dist': {
12    'css': 'dist/css/',
13      html: "dist/",
14  }
15};
16
17gulp.task('sass', done => {
18  gulp.src(paths.src.scss)
19  .pipe(sourcemaps.init())
20  .pipe(sass({
21    outputStyle: 'expanded',
22  }).on('error', sass.logError))
23  .pipe(autoprefixer({
24    browsers: ['last 2 versions'],
25  }))
26  .pipe(sourcemaps.write())
27  .pipe(gulp.dest(paths.dist.css))
28  .pipe(gulp.dest(paths.dist.css));
29  done();
30});
31
32const browserSync = require('browser-sync').create()
33
34gulp.task('serve', done => {
35    browserSync.init({
36        server: {
37            baseDir: './dist',
38            index: 'index.html',
39        },
40    })
41    done()
42})
43
44gulp.task('watch', () => {
45    const browserReload = done => {
46        browserSync.reload()
47        done()
48    }
49
50    gulp.watch('./dist/**/*', browserReload)
51})
52
53gulp.task('default', gulp.series('serve', 'watch'))
54
55const pug = require("gulp-pug");
56
57// setting : Pug Options
58const pugOptions = {
59  pretty: true,
60};
61
62// pugコンパイル
63gulp.task("pug", done => {
64  gulp
65    .src(paths.src.pug)
66    .pipe(
67      plumber({ errorHandler: notify.onError("Error: <%= error.message %>") })
68    )
69    .pipe(pug(pugOptions))
70    .pipe(gulp.dest(paths.public.html));
71  done();
72});
73
74gulp.task("dev", () => {
75  gulp.watch(paths.src.scss, gulp.task('sass'));
76  gulp.watch(paths.src.pug, gulp.task("pug"));
77});

▼package.json

json
1{
2  "name": "sample",
3  "version": "1.0.0",
4  "description": "",
5  "main": "index.js",
6  "scripts": {
7    "test": "echo \"Error: no test specified\" && exit 1",
8    "dev": "gulp dev"
9  },
10  "keywords": [],
11  "author": "",
12  "license": "ISC",
13  "dependencies": {},
14  "devDependencies": {
15    "browser-sync": "^2.26.5",
16    "gulp-autoprefixer": "^6.1.0",
17    "gulp-pug": "^4.0.1",
18    "gulp-sass": "^4.0.2",
19    "gulp-sourcemaps": "^2.6.5"
20  }
21}