UglifyJS2 used by gulp-uglify generates source maps but mapping is incorrect

[dragonflypl]

I have this task to generate bundled & minified JavaScript file:

    return gulp.src(paths)
        .pipe(paths.sortByFilename ? sorter(key) : gulpUtil.noop())
        .pipe(plumber(eh('Error compiling javascript (' + key + ')')))
        .pipe(sourcemaps.init())
        .pipe(gulpBabel())
        .pipe(gulpConcat(key + '.js'))
        .pipe(gulp.dest(cp.build(gomModule) + '/js'))
        .pipe(gulpNgAnnotate({add: true, single_quotes: true}))
        .pipe(gulpUglify())
        .pipe(gulpRename({ extname: '.min.js' }))
        .pipe(sourcemaps.write("."))
        .pipe(gulp.dest(cp.build(gomModule) + '/js'));   

Looks ok: .min.js gets mangled etc and sourcemaps are generated. But unfortunatelly debugging is not possible. Mapping is incorrect - stepping through the code / locals is broken. gulp-uglify seems to be the culprit because if I remove it from the the task, mapping works (with ngAnnotations in place as well as with babel transformation). Any idea that's going on? User versions are:

"gulp-sourcemaps": "^2.1.1",
"gulp-ng-annotate": "~2.0.0",
"gulp-babel": "^6.1.2",
"gulp-concat": "^2.6.0",
"gulp-uglify": "^2.0.0", // uses "uglify-js": "2.7.3",
"gulp-rename": "~1.2.0"

[rvanvelzen]

We are not gulp-uglify. Please report an issue with them.

[g5codyswartz]

@dragonflypl Did you open a ticket with gulp-uglify? I'm trying to figure this same exact issue out right now and Google is bringing me to this ticket.

Edit: found your ticket for anyone else that needs to follow this: terinjokes/gulp-uglify#236