Confusing error message when there is an accidental circular reference in monorepo

[Jack-Works]

🔎 Search Terms

because it would overwrite input file

🕗 Version & Regression Information

• This is the behavior in every version (5.8.3 and 5.9.0-dev.20250330) I tried, and I reviewed the FAQ for entries about "because it would overwrite input file"

⏯ Playground Link

https://github.com/Jack-Works/reproduce/tree/main/ts-accidental-circular-reference

💻 Code

git clone https://github.com/Jack-Works/reproduce/ --filter=blob:none
cd ts-accidental-circular-reference
code .
code ./b/src/index.ts
code ./b/tsconfig.json

🙁 Actual behavior

a error message that is not very helpful at b/tsconfig.json.

Cannot write file 'reproduce/ts-accidental-circular-reference/b/dist/index.d.ts' because it would overwrite input file.ts

🙂 Expected behavior

Despite the error message, tsc should give some helpful information so developers can figure out there is a circular project reference between a and b. Without this kind of information, circular reference is extremely hard to find out in a big monorepo

Additional information about the issue

No response

[RyanCavanaugh]

There is no circular project reference graph here. a has no references https://github.com/Jack-Works/reproduce/blob/main/ts-accidental-circular-reference/a/tsconfig.json

[Jack-Works]

There is no circular project reference graph here. a has no references Jack-Works/reproduce@main/ts-accidental-circular-reference/a/tsconfig.json

There is one, https://github.com/Jack-Works/reproduce/blob/main/ts-accidental-circular-reference/a/src/index.ts a reference b without citing it in the a/tsconfig.json, which is an error, but this error is hard to find out if TypeScript gives an error message like this.

[RyanCavanaugh]

I can't repro that behavior either. This is what I get when trying to infer what you were doing:

Before running pnpm install

D:\Throwaway\reproduce\ts-accidental-circular-reference>tsc -b
a/src/index.ts:1:19 - error TS2307: Cannot find module 'b' or its corresponding type declarations.

1 import { y } from 'b'
                    ~~~

b/src/index.ts:1:19 - error TS2307: Cannot find module 'a' or its corresponding type declarations.

1 import { x } from 'a'
                    ~~~


Found 2 errors.


D:\Throwaway\reproduce\ts-accidental-circular-reference>cd a

D:\Throwaway\reproduce\ts-accidental-circular-reference\a>tsc
src/index.ts:1:19 - error TS2307: Cannot find module 'b' or its corresponding type declarations.

1 import { y } from 'b'
                    ~~~


Found 1 error in src/index.ts:1


D:\Throwaway\reproduce\ts-accidental-circular-reference\a>cd ..\b

D:\Throwaway\reproduce\ts-accidental-circular-reference\b>tsc
src/index.ts:1:19 - error TS2307: Cannot find module 'a' or its corresponding type declarations.

1 import { x } from 'a'
                    ~~~


Found 1 error in src/index.ts:1

After running pnpm install

D:\Throwaway\reproduce\ts-accidental-circular-reference\a>tsc

D:\Throwaway\reproduce\ts-accidental-circular-reference\a>cd ..\b

D:\Throwaway\reproduce\ts-accidental-circular-reference\b>tsc

D:\Throwaway\reproduce\ts-accidental-circular-reference\b>cd ..

D:\Throwaway\reproduce\ts-accidental-circular-reference>tsc -b