Gulp 4.0.0 not terminating when tasks complete

[curtisc123-zz]

The Gulp process just hangs on finishing and does not complete. CI won't continue so I can't just terminate it manually. This is on Windows 10. I've also added in a process.exit() but then I get this Did you forget to signal async completion? error.

I've tried several different plugins and tasks, but it happens on all of them. Killed all node process, even restarted my computer, but it's still happening.

const gulp = require('gulp');
const less = require('gulp-less');
const stylelint = require('gulp-stylelint');
const cssmin = require('gulp-cssmin');

function stylelintTask () {
	return gulp.src(`${srcDir}/**/*.less`)
		.pipe(stylelint({
			failAfterError: false,
			reporters: [
				{ 
					console: true,
					formatter: 'verbose',  
				},
			],
		}));
}

function lessTask () {
	return gulp.src(`${srcDir}/css/all.less`)
		.pipe(less().on('error', (error) => { console.log(error) }))
		.pipe(cssmin().on('error', (error) => { console.log(error) }))
		.pipe(gulp.dest(`${distDir}/css/`))
}

gulp.task('less', gulp.series(stylelintTask, lessTask));

Windows 10 Environment
Gulp - 4.0.0
Node - 8.11.1
NPM - 5.6.0

Any insight would be great.

[phated]

https://github.com/mafintosh/why-is-node-running