This outdated version of gulp depends on (at least) outdated node-vinyl-fs and node-first-chunk-stream and unpackaged node-glob-watcher. That's why tests fail, this reveals that "auto-rebuild" feature is unusable. I hope nothing else is broken.
To avoid uploading a major change during Buster freeze, I packaged gulp with tests related to Gulp.watch() disabled and with a patch to throw an error that points here if vinyl-fs.watch() is called. Cheers, Xavier