[Vite 3] Legacy Build Bug

[brillout]

Describe the bug

SSR deps don't seem to be externalized by default (and even when added to ssr.external). With legacy.buildPluginCommonjs set to true. (Same thing as #8880: vite-plugin-ssr ist not externalized even though it should.)

The reproduction linked here is the same reproduction as the one linked at #8880 but with legacy.buildPluginCommonjs set to true.

Note that the reproduction is green in vite-plugin-ssr's CI (the reproduction is a subset of the CI). The difference with the CI is that vite-plugin-ssr is symlinked in the CI. So I'm suspecting some kind of node_modules if-branch to be the culprit.

Reproduction

https://github.com/brillout/vite-3-legacy-build-bug

System Info

System:
    OS: Linux 5.10 Debian GNU/Linux 10 (buster) 10 (buster)
    CPU: (2) x64 Intel(R) Celeron(R) N4020 CPU @ 1.10GHz
    Memory: 423.00 MB / 2.71 GB
    Container: Yes
    Shell: 5.0.3 - /bin/bash
  Binaries:
    Node: 18.0.0 - ~/.config/nvm/versions/node/v18.0.0/bin/node
    Yarn: 1.22.17 - /usr/local/bin/yarn
    npm: 8.6.0 - ~/.config/nvm/versions/node/v18.0.0/bin/npm
  Browsers:
    Firefox: 97.0.1
  npmPackages:
    vite: ^2.8.4 => 3.0.0-beta.7

Used Package Manager

pnpm

Logs

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[patak-dev]

So IIUC, vite-plugin-ssr is working correctly out of CI. Is that also the case for #8880?

[brillout]

for #8880?

Actually, it's another bug in CI.

Bug in CI: https://github.com/brillout/vite-plugin-ssr/runs/7221842235?check_suite_focus=true (see https://github.com/brillout/vite-plugin-ssr/commits/vite%403.0.0-beta.7).