watch build generates wrong build manifest

[hi-ogawa]

Describe the bug

It looks like manifest plugin doesn't reset properly between watch rebuild. What's the intent of not resetting this.manifest too? The issue reproduces on Vite 5 as well.

vite/packages/vite/src/node/plugins/manifest.ts

Lines 30 to 39 in 6dbd4b0

	export function manifestPlugin(): Plugin {
	const getState = usePerEnvironmentState(() => {
	return {
	manifest: {} as Manifest,
	outputCount: 0,
	reset() {
	this.outputCount = 0
	},
	}
	})

(For the context, I was investigating a similar issue on double rsc environment builds with rolldown-vite hi-ogawa/vite-environment-examples#154. Though my issue somehow doesn't show up on current vite, I just found a similar issue with current vite's watch build.)

Reproduction

https://stackblitz.com/github/hi-ogawa/reproductions/tree/main/rolldown-vite-watch-build-manifest?file=src%2Fmain.js

Steps to reproduce

• open stackblitz and run vite build --watch
• see dist/.vite/manifest.json includes src/dep.js
• edit src/main.js to remove import("./dep.js")
• see dist/.vite/manifest.json still includes src/dep.js

$ pnpm build --watch
vite v6.0.11 building for production...

watching for file changes...

--- 1st build ---
build started...
✓ 5 modules transformed.
dist/.vite/manifest.json       0.31 kB │ gzip: 0.18 kB
dist/index.html                0.32 kB │ gzip: 0.23 kB
dist/assets/dep-D1M531Dn.js    0.02 kB │ gzip: 0.04 kB
dist/assets/index-6lgMnd3v.js  3.35 kB │ gzip: 1.25 kB
built in 61ms.

--- 2nd build ---
build started...
✓ 1 modules transformed.
dist/.vite/manifest.json       0.26 kB │ gzip: 0.16 kB
dist/index.html                0.32 kB │ gzip: 0.23 kB
dist/assets/index-X0jGllOl.js  1.29 kB │ gzip: 0.53 kB
built in 21ms.

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (8) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vite: ^6 => 6.0.11

Used Package Manager

pnpm

Logs

No response

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