merge at end of chain doesn't complete task

[stevenvachon]

const es = require("event-stream");

function css() {
  const docs = gulp.src("./less/docs.less")
    .pipe( less(lessOptions) )
    .pipe( concat("docs.css") )
    .pipe( gulp.dest("./docs/") );

  const framework = gulp.src("./less/framework.less")
    .pipe( less(lessOptions) )
    .pipe( concat("framework.css") )
    .pipe( gulp.dest("./build/") )
    .pipe( gulp.dest("./docs/") );

  return es.merge(docs, framework);
}

[14:08:35] The following tasks did not complete: css
[14:08:35] Did you forget to signal async completion?

It completes the task, however, when followed by another pipe in the chain:

return es.merge(docs, framework)
  .pipe( gulp.dest("./docs/") );

[stevenvachon]

@dominictarr ?

merge-stream works, though -- switching to that.

[roydukkey]

I believe this is the same issue. https://stackoverflow.com/questions/51255885

[Kocal]

It happens to me after updating to Gulp 4.
Thanks @stevenvachon for opening an issue and giving a solution 😎

[right9ctrl]

Added note for gulp users in readme.