`--build --dry` reports a noEmit project reference as perpetually out of date (expects emitted output that noEmit never produces)

[schickling-assistant]

Search Terms

noEmit --build --dry, tsconfig.tsbuildinfo noEmit dry build, noEmit index.js does not exist dry build, build dry noEmit project references out-of-date

Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ for entries about --build, noEmit, and project references.
• Reproduced with typescript@5.9.3.
• Reproduced with typescript@next version 7.1.0-dev.20260717.1.
• Also reproduced with the TypeScript-Go port, tsgo version 7.0.0-dev+effect-tsgo.0.14.5.

Playground Link

No Playground link. This requires a multi-tsconfig.json project-reference graph and tsc --build --dry.

Code

tsconfig.json

{
  "files": [],
  "references": [
    {
      "path": "./lib"
    }
  ]
}

lib/tsconfig.json

{
  "compilerOptions": {
    "noEmit": true
  },
  "files": ["index.ts"]
}

lib/index.ts

export const value = 1

Run:

tsc --version
tsc --build tsconfig.json --dry --noCheck --verbose
tsc --build tsconfig.json --verbose
tsc --build tsconfig.json --dry --noCheck --verbose
tsc --build tsconfig.json --verbose
tsc --build tsconfig.json --dry --noCheck --verbose
tsc --build tsconfig.json --dry --verbose

Actual behavior

The first dry run reports the referenced noEmit project as out of date because build info does not exist:

Version 5.9.3

Projects in this build:
    * lib/tsconfig.json
    * tsconfig.json

Project 'lib/tsconfig.json' is out of date because output file 'lib/tsconfig.tsbuildinfo' does not exist
A non-dry build would build project '/tmp/ts-noemit-dry-repro/lib/tsconfig.json'

A non-dry build creates lib/tsconfig.tsbuildinfo but, correctly, does not create lib/index.js because noEmit is enabled:

Project 'lib/tsconfig.json' is out of date because output file 'lib/tsconfig.tsbuildinfo' does not exist
Building project '/tmp/ts-noemit-dry-repro/lib/tsconfig.json'...

After that, repeated dry and non-dry builds keep reporting the project as stale because lib/index.js does not exist:

Project 'lib/tsconfig.json' is out of date because output file 'lib/index.js' does not exist
A non-dry build would build project '/tmp/ts-noemit-dry-repro/lib/tsconfig.json'

This remains true after a second non-dry build:

Project 'lib/tsconfig.json' is out of date because output file 'lib/index.js' does not exist
Building project '/tmp/ts-noemit-dry-repro/lib/tsconfig.json'...

Project 'lib/tsconfig.json' is out of date because output file 'lib/index.js' does not exist
A non-dry build would build project '/tmp/ts-noemit-dry-repro/lib/tsconfig.json'

It is not specific to --noCheck; tsc --build tsconfig.json --dry --verbose reports the same missing lib/index.js output after the project has been built.

Expected behavior

Question: is this intended for noEmit projects in a --build references graph?

If this project shape is supported, I would expect build up-to-date logic not to require emitted JavaScript outputs for a project whose compilerOptions.noEmit guarantees those outputs will never exist. After a non-dry build creates the relevant build info, --build --dry should not report the project as perpetually needing a build because lib/index.js is missing.

If this project shape is not supported, it would be useful for --build to report that directly rather than producing a perpetual stale-output result.

Additional information about the issue

The same repro also appears in the TypeScript-Go port:

Version 7.0.0-dev+effect-tsgo.0.14.5

Project 'lib/tsconfig.json' is out of date because output file 'lib/tsconfig.tsbuildinfo' does not exist
A non-dry build would build project '/tmp/tsgo-noemit-dry-repro/lib/tsconfig.json'

Building project 'lib/tsconfig.json'...

Project 'lib/tsconfig.json' is out of date because output file 'lib/index.js' does not exist
A non-dry build would build project '/tmp/tsgo-noemit-dry-repro/lib/tsconfig.json'

Posted on behalf of @schickling

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agent_name	💎 co1-zenith
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agent_tool	Codex CLI
agent_tool_version	0.144.1
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runtime_profile	/nix/store/1n76sy6i9y3ki3k4w04jksqvygw67sj0-coding-agent-runtime-profile/share/coding-agents/profile.json
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worktree	effect-utils/schickling/2026-07-17-tsgo-refactor
machine	dev3
tooling_profile	dotfiles@4eac376

[RyanCavanaugh]

This is a confusing premise. Why are you writing a reference to a project with noEmit on in the first place? This effectively "does nothing" as far as I'm aware.