Gulp run-sequence "'taskname' is a not valid task string" error

Question

I faced a stange problem. Tasks sequence is right, syntax too, but it's not working and trowns an error:

const gulp = require("gulp");
const runSequence = require('run-sequence');
gulp.task("Markup-Build", function(callback) {
    return runSequence("Markup-Clean", [
        ["Markup-Build-Styles", "Markup-Collect-Styles"],
        ["Markup-Build-Views", "Markup-Collect-Views"]
    ], callback);
});

I need some help. What I doing wrong?

(Dependent tasks are working, I checked names too, no misprints)

Answer 1

you cant have nested array change it to

  return runSequence("Markup-Clean",
    ["Markup-Build-Styles", "Markup-Collect-Styles"],
    ["Markup-Build-Views", "Markup-Collect-Views"]
, callback);