Convert gulp watch in gulp@3.9.1 to gulp@4

Question

We are switching from gulp@3.9.1 to gulp@4 and are having trouble switching over. When we run gulp watch, we are getting the following

Answer 1

I just ran into this a couple days ago myself. What worked for me was to run each task in its own gulp.watch() with the gulp.series() on the watch task call instead of the watch task itself. For example:

gulp.task('watch', function() {
  gulp.watch(src.js, gulp.series('minify-js'));
  gulp.watch(src.css, gulp.series('minify-css'));
});