The dts bundler emits plain import { ... } and export { ... } for symbols that the source declared as type-only, instead of import type { ... } / export { type ... }.

Reproduced on rolldown-plugin-dts@0.24.0-beta.1 with rolldown@1.0.0-rc.17.

Under rolldown 1.0.0-rc.17, this becomes a hard build failure when the imported names are not value exports of the importee — rolldown rc.17 promoted MISSING_EXPORT between TS modules from a warning to an error in rolldown#9197 (commit cc38b86). Builds that previously emitted this as silenced warnings now abort with errors like:

[MISSING_EXPORT] Error: "Foo" is not exported by "node_modules/some-pkg/index.d.ts".

Minimal reproduction

package.json:

{"type":"module","devDependencies":{"rolldown":"1.0.0-rc.17","rolldown-plugin-dts":"0.24.0-beta.1","typescript":"6.0.3"}}

rolldown.config.ts:

import {defineConfig} from "rolldown";
import {dts} from "rolldown-plugin-dts";

export default defineConfig({
  input: "src/index.ts",
  external: ["pkg"],
  plugins: [dts()],
});

src/index.ts:

declare module "pkg" {
  export const value: number;
  export type T = string;
}

import {value} from "pkg";
import type {T} from "pkg";

export const x = value;
export type Y = T;

Run:

pnpm install
pnpm exec rolldown -c

Actual output (dist/index.d.ts)

import { T } from "pkg";        // T is type-only — no `type` modifier

declare module "pkg" {
  const value: number;
  type T = string;
}
declare const x: any;
type Y = T;

export { Y, x };                // Y is a type — no `type` modifier

Expected output

import type { T } from "pkg";

declare module "pkg" {
  const value: number;
  type T = string;
}
declare const x: any;
type Y = T;

export { type Y, x };

Real-world impact

In a real project with verbatimModuleSyntax: true and an external module that uses export = X (e.g. dayjs — Dayjs, ConfigType, OpUnitType, OptionType only exist via the namespace), the missing type modifier turns those names into invalid value imports. With rolldown rc.17 the build fails with multiple MISSING_EXPORT errors aggregated from the dts bundling step.

Versions

rolldown-plugin-dts: 0.24.0-beta.1 (also reproduces on 0.23.2)
rolldown: 1.0.0-rc.17
typescript: 6.0.3

Related

• rolldown#9197 — the rolldown change that surfaces this
• export * loses type modifiers when flattening re-exports #95 — same shape (type modifier dropped) but for export * re-exports

This issue was written with the help of Claude Opus 4.7