javascript - How can I use gulp concat with a mix of remote and local files? -

this not working well:

gulp.task('dev', function () {     console.log('concatenating development libs...')      var log = function (file, cb) {         console.log(file.path);         cb(null, file);     };      var zocialcss = 'zocial-flat.css';     request('http://my.blob.core.windows.net/shared-styles-webfonts/zocial-flat.css')         .pipe(fs2.createwritestream(zocialcss));      var cssfiles = [         './' + zocialcss,         '../bower_components/**/bootstrap.css',     ];      fs.src(cssfiles)         .pipe(map(log))         .pipe(concat('styles.css'))         .pipe(gulp.dest(stylespath)); }); 

my guess fs2.createwritestream(zocialcss) keeps file locked (or open writing) , never closes, concat ignores (or silently fails). can see zocial-flat.css being generated expected (i would, way, delete file after concatenation).

i have seen alternatives approach (like gulp-remote-src) , open such suggestions.