file system watcher does not handle normal file system data races

[rbtcollins]

I'm filing this here from microsoft/vscode#162551 where they identified it as coming from parcel's watcher.

Type: Bug

Reproduction is hard, but something like the following should work:

1. use something like Rust where compiling can put a lot of load on the system, with a LSP that will start up when vscode does, and uses randomly named directories in the source tree. Rust-analyzer in particular triggers this.
2. have a very large project - I found this with a workspace with 10 different rust projects, each of which had 300-400 dependencies
3. start vscode, it will trigger the LSP which will start building.

Now, when the race happens something like the following is logged:
[2022-10-03 11:09:21.334] [renderer1] [error] [File Watcher (parcel)] Unexpected error: inotify_add_watch on '/home/robertc/Documents/src/projectname/target/debug/deps/rmetaWmhbGH' failed: No such file or directory (EUNKNOWN) (path: /home/robertc/Documents/src/projectname)
[2022-10-03 11:09:21.336] [renderer1] [error] [File Watcher (universal)] restarting watcher after error: inotify_add_watch on '/home/robertc/Documents/src/projectname/target/debug/deps/rmetaWmhbGH' failed: No such file or directory

What is happening here as far as I can tell is that the parent directory watch (on deps) informs the watcher that a new child directory exists (rmetaWmhbGH in this case). Then an arbitrary amount of time passes (this is why you need a loaded system, and the watcher now adds the recursive watch for this directory. However in the intervening time, the new directory was deleted again.

This is a totally normal thing to happen. tl;dr inotify_add_watch errors of the kind ENOENT should be ignored.

VS Code version: Code 1.71.2 (74b1f979648cc44d385a2286793c226e611f59e7, 2022-09-14T21:12:14.256Z)
OS version: Linux x64 5.15.0-48-generic snap
Modes:
Sandboxed: No

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz (8 x 1500)
GPU Status	2d_canvas: unavailable_software canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software webgpu: disabled_off
Load (avg)	4, 3, 5
Memory (System)	30.94GB (16.25GB free)
Process Argv	--no-sandbox --force-user-env --unity-launch --crash-reporter-id 48f00fd1-b54e-4dc0-8575-34d6b8dbef5f
Screen Reader	no
VM	0%
DESKTOP_SESSION	ubuntu
XDG_CURRENT_DESKTOP	Unity
XDG_SESSION_DESKTOP	ubuntu
XDG_SESSION_TYPE	wayland

Extensions (45)

Extension	Author (truncated)	Version
vscode-bazel	Baz	0.5.0
gitlens	eam	12.2.2
EditorConfig	Edi	0.16.4
vscode-pull-request-github	Git	0.50.0
go	gol	0.35.2
terraform	has	2.24.2
vscode-test-explorer	hbe	2.21.1
vscode-test-explorer-liveshare	hbe	1.0.5
rust-test-lens	hde	1.0.0
golang-tdd	joa	0.0.9
rust-doc-viewer	JSc	3.0.4
vscode-docker	ms-	1.22.1
kind-vscode	ms-	0.0.3
vscode-kubernetes-tools	ms-	1.3.10
python	ms-	2022.14.0
vscode-pylance	ms-	2022.9.40
jupyter	ms-	2022.8.1002431955
jupyter-keymap	ms-	1.0.0
jupyter-renderers	ms-	1.0.9
remote-containers	ms-	0.251.0
test-adapter-converter	ms-	0.1.6
vsliveshare	ms-	1.0.5733
cargo	pan	0.2.3
vscode-yaml-sort	Pas	5.5.0
fabric8-analytics	red	0.3.6
java	red	1.11.0
vscode-xml	red	0.21.0
vscode-yaml	red	1.10.1
rust-analyzer	rus	0.3.1229
jsonnetng	Seb	1.3.0
crates	ser	0.5.10
rewrap	stk	1.16.3
vscode-rust-test-adapter	Swe	0.11.0
even-better-toml	tam	0.18.1
vscode-lldb	vad	1.8.0
intellicode-api-usage-examples	Vis	0.2.4
vscodeintellicode	Vis	1.2.28
vscode-java-debug	vsc	0.44.0
vscode-java-dependency	vsc	0.21.0
vscode-java-pack	vsc	0.25.3
vscode-java-test	vsc	0.37.1
vscode-maven	vsc	0.39.0
pestfile	xor	0.3.0
rust-extension-pack	Zer	1.1.0
vscode-proto3	zxh	0.5.5

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