Gulp 4 watcher is running but does not detect changes - gulp

Question

I'm having the following file structure:
/ src
-- app.less
/ gulp
-- index.js
-- gulpfile.js
This file structure is mounted in a vagrant box in /vagrant which means the path to app.less becomes /vagrant/src/app.less. Yes, I've checked this.
gulpfile.js
require('./gulp');
index.js
var paths = {
less: '/vagrant/src/app.less'
};
gulp.task('less', function () {
console.log('less function running');
return gulp.src(paths.less)
.pipe(less());
});
gulp.task('watch:styles', function () {
console.log('watch function running');
gulp.watch(paths.less, gulp.series('less'));
});
gulp.task('watch', gulp.parallel('watch:styles'));
gulp -v returns:
[10:02:05] CLI version 0.4.0
[10:02:05] Local version 4.0.0-alpha.1
gulp watch returns:
[09:45:20] Using gulpfile /vagrant/gulpfile.js
[09:45:20] Starting 'watch'...
[09:45:20] Starting 'watch:styles'...
watch function running
I've been using Gulp 4 for over 2 months without problems with the watcher. Since last week the watcher is not responding to files that are being changed. I've tried several editors, I've tried multiple paths like '/vagrant/**/*.less' and '../src/*.less' and even the absolute path to app.less '/vagrant/src/app.less', none of them worked.
After some research I found several issues on the github repo of Gulp 4 about the watcher. Yet, I can't figure out what the problem is. Maybe I'm overlooking an error in my code or something new in the docs, but I'm trying to solve this since yesterday morning without any luck.

Answer 1

It appears you're using Vagrant. If you have Gulp running on your Vagrant machine instead of on the host it won't detect any changes to files that you make on the host. This is because the events that notify the OS about filesystem changes don't propagate into the VM.
If this is the case, the solution is to simply run Gulp wherever you actually make changes to the files (i.e. if you make the changes on the VM, run it on the VM, if you make changes on the host, run Gulp on the host).
Also maybe make the path relative, instead of tying your implementation to your Vagrant box. i.e. less: './src/app.less'.