Panic when watching auto-rebulding blog

[matklad]

This is probably a bug in notify, and it really warrants more investigation on my side, but I don't have time for this right now, so I'll log the issue as I've got it.

Feel free to ignore this! While I am sure it is actionable (there's an honest-to-god panic), I bet this'll be fiddly to debug.

When running deno task watch & live-server --port 8080 in https://github.com/matklad/matklad.github.io, I got the following panic:

src/main.ts watch
[2024-03-22T10:28:45Z INFO  live_server::server] Listening on http://172.20.10.6:8080/
[2024-03-22T10:28:45Z INFO  live_server::watcher] Listening on /home/matklad/p/matklad.github.io
thread 'tokio-runtime-worker' panicked at /home/matklad/.cargo/registry/src/index.crates.io-6f17d22bba15001f/live-server-0.7.0/src/watcher.rs:74:10:
called `Result::unwrap()` on an `Err` value: Error { kind: Io(Os { code: 2, kind: NotFound, message: "No such file or directory" }), paths: ["/home/matklad/p/matklad.github.io/out/res/2021/11/07"] }
stack backtrace:
Watcher Process started.
   0: rust_begin_unwind
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:72:14
   2: core::result::unwrap_failed
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/result.rs:1649:5
   3: live_server::watcher::watch::{{closure}}
   4: std::panicking::try
   5: tokio::runtime::task::harness::Harness<T,S>::poll
   6: tokio::runtime::scheduler::multi_thread::worker::Context::run_task
   7: tokio::runtime::scheduler::multi_thread::worker::Context::run
   8: tokio::runtime::context::scoped::Scoped<T>::set
   9: tokio::runtime::context::runtime::enter_runtime
  10: tokio::runtime::scheduler::multi_thread::worker::run
  11: <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll
  12: tokio::runtime::task::core::Core<T,S>::poll
  13: tokio::runtime::task::harness::Harness<T,S>::poll
  14: tokio::runtime::blocking::pool::Inner::run
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.
thread 'main' panicked at /home/matklad/.cargo/registry/src/index.crates.io-6f17d22bba15001f/live-server-0.7.0/src/main.rs:43:28:
called `Result::unwrap()` on an `Err` value: JoinError::Panic(Id(22), ...)
stack backtrace:
   0: rust_begin_unwind
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/std/src/panicking.rs:645:5
   1: core::panicking::panic_fmt
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/panicking.rs:72:14
   2: core::result::unwrap_failed
             at /rustc/07dca489ac2d933c78d3c5158e3f43beefeb02ce/library/core/src/result.rs:1649:5
   3: tokio::runtime::park::CachedParkThread::block_on::{{closure}}
   4: tokio::runtime::context::blocking::BlockingRegionGuard::block_on
   5: tokio::runtime::context::runtime::enter_runtime
   6: tokio::runtime::runtime::Runtime::block_on
   7: live_server::main
note: Some details are omitted, run with `RUST_BACKTRACE=full` for a verbose backtrace.

Notably, the "root" path there should be /home/matklad/p/matklad.github.io/! The out directory is the one that's deleted and re-created by deno task watch part.

So, it looks like what's happening here is that you ask notify to watch ./, it interanlly races to read ./out/res/2021/11/07, and that fails. This is normal: we are watching fs for changes, of course we are expected files to go out of existence from under our nose! What is strage is that notify propagates this error all the way up to watcher creation, and fails the entire operation.

Thanks for live-server by the way, its best in class from what I can tell, no nonsense, does exactly what I need it to!

[matklad]

welp, spend 10 more seconds looking at the source code and debugged this! Let me file an issue on notify...