Callback not running

[nachtfunke]

So I have noticed that for some reason the callback is just not running at all.

This is the task.

function minifyCssDest() {
    'use strict'
    return gulp
        .src(local.assetsDist + '/*.css')
        .pipe(
            cleanCSS({ debug: true }, details => {
                log.info(
                    '[cleanCSS]',
                    dye.yellow(
                        ` minifying from ${details.name}: ${
                            details.stats.originalSize
                        }`
                    )
                )
                log.info(
                    '[cleanCSS]',
                    dye.green(
                        ` => to ${details.name}: ${details.stats.minifiedSize}`
                    )
                )
            })
        )
        .pipe(
            plumber({
                errorHandler: err => {
                    log.error(
                        '[cleanCSS]',
                        dye.red(` something went wrong while minifying: ${err}`)
                    )
                    done()
                },
            })
        )
        .pipe(gulp.dest(local.sass.dest))
}

Does anyone spot any issues here? I am a bit lost. The code hasn't changed since it was setup and it used to work just fine, it just stopped working.