Building @parcel/watcher was always a huge PITA. I also hope they release this package separately because it’d be nice to have an easy to install, on any OS, file watcher that doesn’t require C++ toolchain.
Or recently I use an eBPF-based file watcher. This needs the client to run a transient process with cap_perfmon and cap_bpf that sets up the ring buffers and exits. After that, any unpriveleged process can read from that ring buffer at any time and it just works.
inotify works just fine for stuff like project watchdirs, but I wanted one for a whole home directory where it had lots of issues, fd limits, race conditions in situations like mkdir -p a/b, and renames/mv being hard to deal with, etc.