Relative assets path with multiple entries

[noobnooc]

Describe the bug

I am building an embedded multiple entries project, it has a config file like this:

  {
    root: "src/pages",
    base: "./",
    build: {
      outDir: "../../build/pages",
      emptyOutDir: true,
      rollupOptions: {
        input: {
          page1: resolve(__dirname, "src/pages/page1/index.html"),
          page2: resolve(__dirname, "src/pages/page2/index.html")
        }
      }
    }
  }

But the built files looks a little strange, the html files are not reference to the asset files correctly. I attempted to change the base field to ../, but nothing is changed.

Reproduction

https://codesandbox.io/s/recursing-orla-m6p97e?file=/build/pages/page1/index.html:281-287

System Info

System:
    OS: macOS 12.3.1
    CPU: (10) arm64 Apple M1 Max
    Memory: 137.45 MB / 32.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 17.1.0 - /usr/local/bin/node
    Yarn: 1.22.17 - /usr/local/bin/yarn
    npm: 8.3.0 - /usr/local/bin/npm
  Browsers:
    Chrome: 100.0.4896.127
    Firefox: 99.0
    Safari: 15.4

Used Package Manager

yarn

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

duplicate of #4517