Paths from tsconfig are not used if declaration is on a different partition

@andrewbranch is already working on this.

Since May 15, 2026.

### 🔎 Search Terms

paths drive partition

### 🕗 Version & Regression Information

- This changed between versions 5.6 and 5.7 (before this paths was not used in the give example)

### ⏯ Playground Link

[Playground Link](https://www.typescriptlang.org/dev/bug-workbench/?ssl=32&ssc=32&pln=1&pc=1#code/PTAEAEBMFMGMBsCGAnRAXAlgewHYCgQIAzDeaHRAW2gC5QBhG4AZ2VmAxxgA8A6NZngyUADlmRpQAb1AARAIygAvqCLIslUACJeHHGmjIK8LUNHjJM2QCZlq9Zp16DRxCbzRuYiaFi5mkgBCigC8cvIeXha+-kG2YTZ4BGDgJGQU1HSMLGzOhsb8gsLelqAAMgCSgaCIzOVV8ipqGtrg8BgARvJaANxmJdL11bVDtk0Ore0d1r1JngN+OAHhoGEA2pXBALo1dYsBkQuxcvGgG1XWOyP7aEkgqaTkVLSgAoskAOa8AFbMuHhSPCgYHaPyiR7IADyIkw-i0dEBIKR2gCyAwsDQ8NeyAArtAADRA5HArRYHFoWQYZBYnS6MmYwnEkkwBAodDYHBYtC4glE4laEToAAWzCxiKZSK0bU63Toay02SmzD0PF4kEKWi2jIlIKlUxmcq0siYSpVnjVGq2fORSmttttyWIjwyL0VnWVU0Kh2iNyGoBoOJwGAAjnjQMwAJ6UDpYeB3FJpJ6ZOQm93AT0Cb0+X2bf2BkNhyPR2NAA)

### 💻 Code

```ts
// @declaration
// @filename: C:/src/index.ts
import { D1 } from "./internal"
import { D2 } from "./internal"
export const B1 = D1
export const B2 = D2

// @filename: C:/src/internal.ts
import { LIB as LIB1} from "@lib1";
import { LIB as LIB2 } from "@lib2";

export const D1 = [LIB1] as const
export const D2 = [LIB2] as const

//@filename: tsconfig.json
{
"compilerOptions": {
"strict": true,
"outDir": "../out",
"declaration": true,
"paths": {
"@lib1": ["C:/libs/index.d.ts"],
"@lib2": ["D:/libs/index.d.ts"]
}
}
}

// @filename: C:/libs/lib.ts
export const LIB :unique symbol

// @filename: D:/libs/lib.ts
export const LIB :unique symbol
```

### 🙁 Actual behavior

In `index.d.ts` we get:

```ts
export declare const B1: readonly [typeof import("@lib1").LIB];
export declare const B2: readonly [typeof import("D:/dev/tmp/app").LIB];
```

### 🙂 Expected behavior

We should get

```ts
export declare const B1: readonly [typeof import("@lib1").LIB];
export declare const B2: readonly [typeof import("@lib2").LIB];
```

### Additional information about the issue

The workbench does not actually show the bug since it does not appear to suport windows rooted drive paths. The issue only happens if the d.ts file is on a different drive. There is an explicit check in the code see if the declaration path is relative and only then is the path alias in tsconfig used (which doesn't seem right).