v4: all packages are inlined with `deps.optimizer` ("Sourcemap for ... points to missing files", when using `deps.optimizer.{mode}.enabled` and `include`)

[fpapado]

Describe the bug

After upgrading from v3 to v4, we started seeing sourcemap warnings when running tests.

These warnings come from libraries in node_modules, and as far as I can see, point to existing sourcemap files on disk, such as this:

Sourcemap for "/Users/fotis/oss/vitest-optimizer-sourcemap/node_modules/.pnpm/domutils@3.2.2/node_modules/domutils/lib/esm/feeds.js" points to missing source files

I have narrowed this down to the use of deps.optimizer.ssr.enabled, but these warnings are emitted even for packages unrelated to those being optimized. I am including more info in the reproduction step below 😌

(I vaguely remember seeing these warnings in past Vitest versions, but they had gone away for a while 💭 )

Reproduction

I have a reproduction at https://github.com/fpapado/vitest-optimizer-ssr-sourcemap-warning, simply:

nvm use
corepack enable

pnpm install
pnpm test

and expect to see warnings about sourcemaps pointing to missing files.

Some additional info:

• Using vitest v3 (pnpm add -DE vitest@3) shows no such warnings
• In v4, if deps.optimize.ssr.enabled is true, but include is empty or not defined, then there are no warnings
• In v4, it does not matter whether the optimizer is enabled for the specific files that are logged; many seemingly unrelated packages will emit these warnings

Please let me know if there is any other info that I can provide, and I'll get back to you!

System Info

System:
    OS: macOS 15.6.1
    CPU: (10) arm64 Apple M1 Pro
    Memory: 3.05 GB / 32.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 24.11.0 - /Users/fotis/.local/state/fnm_multishells/16092_1762799422618/bin/node
    npm: 11.6.1 - /Users/fotis/.local/state/fnm_multishells/16092_1762799422618/bin/npm
    pnpm: 10.15.0 - /Users/fotis/.local/state/fnm_multishells/16092_1762799422618/bin/pnpm
  Browsers:
    Chrome: 142.0.7444.60
    Chrome Canary: 144.0.7520.0
    Firefox: 144.0.2
    Firefox Developer Edition: 145.0
    Safari: 26.0.1
    Safari Technology Preview: 26.0
  npmPackages:
    vite: 7.2.2 => 7.2.2
    vitest: 4.0.8 => 4.0.8

Used Package Manager

pnpm

Validations

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• 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.
• 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.

[colin969]

I'm hesitant to consider my issue a duplicate, but just to note down for the inevitable future when this issue is closed and I have to reopen my own, here's this warning in a repo with completely default options caused by a single import line which occurs both on v3 and v4.

https://stackblitz.com/edit/vitest-dev-vitest-gtlwsofg?file=test%2Fbasic.test.ts

[hi-ogawa]

These warnings come from libraries in node_modules, and as far as I can see, point to existing sourcemap files on disk,

This looks indeed different from other (and past) issues. I haven't checked the connection with Vitest's optimizer specifically, but the warning can be reproduced with noExternal: ["cheerio", "cheerio-select"]. It also reproduces with Vite alone, so it looks like a upstream bug in this regard https://stackblitz.com/edit/github-dgssk1sz?file=repro-vite.js

❯ node repro-vite.js
Sourcemap for "/home/projects/github-dgssk1sz/node_modules/cheerio-select/lib/esm/index.js" points to missing source files
Sourcemap for "/home/projects/github-dgssk1sz/node_modules/cheerio-select/lib/esm/helpers.js" points to missing source files
Sourcemap for "/home/projects/github-dgssk1sz/node_modules/cheerio-select/lib/esm/positionals.js" points to missing source files
Hello World

[hi-ogawa]

Actually the warning seems sensible for Vite. It turned out the source map of those packages use raw github URL for sourceRoot (the build script is in https://github.com/cheeriojs/cheerio-select/blob/a50c8c05cf037dae1336b386925a649fe62a5986/package.json#L39):

• node_modules/cheerio-select/lib/index.d.ts.map

{
  "version":3,
  "file":"index.js",
  "sourceRoot":"https://raw.githubusercontent.com/cheeriojs/cheerio-select/ef063a6ca4c3f0d02d2fc3505e750b6fb81c448d/src/",
  "sources":["index.ts"],
  ...

Vite obviously doesn't try to fetch all these files and assumes local file, and thus shows missing source files warning.

In terms of Vitest issue, probably there was some change in noExternal behavior on v4, which is something we should figure out.