Build hangs indefinitely with ~3000 unbundled entry files

[alexx855]

Reproduction link or steps

https://github.com/roninbuilders/contracts

git clone https://github.com/roninbuilders/contracts.git
cd contracts
pnpm install
pnpm run build

tsdown.config.ts:

import { defineConfig } from 'tsdown'

export default defineConfig({
  entry: ['src/index.ts', 'src/contract.ts', 'src/contracts/**/*.ts'],
  format: ['esm', 'cjs'],
  dts: {
    isolatedDeclarations: true,
  },
  clean: true,
  minify: false,
  outDir: 'dist',
  unbundle: true,
})

• tsdown: 0.19.0-beta.3
• Node.js: v22.x
• OS: Linux

What is expected?

Build completes and outputs ESM + CJS files to dist/.

The project has ~3000 entry files (auto-generated smart contract ABIs). With tsup, this build completes in ~27 seconds.

What is actually happening?

Build hangs indefinitely after displaying:

ℹ tsdown v0.19.0-beta.3 powered by rolldown v1.0.0-beta.58
ℹ config file: /home/alex/dev/contracts/tsdown.config.ts
ℹ entry: src/contract.ts, src/index.ts, src/contracts/...
ℹ target: node18.0.0
ℹ tsconfig: tsconfig.json
ℹ Build start
ℹ Cleaning 11877 files

The process never progresses past "Cleaning X files". CPU usage remains low, suggesting the process is blocked rather than doing intensive work.

Any additional comments?

Tested configurations (all hang):

Setting	Values Tested
dts	true, false, { isolatedDeclarations: true }
minify	true, false
tsdown version	0.19.0-beta.2, 0.19.0-beta.3

The issue appears to be in the core build process, not DTS or minification, since disabling both doesn't resolve the hang.

Related issues:

• minification with unbundle results in unoptimized output #447 - minification with unbundle
• Build in parallel to speed up build time #541 - parallel builds not implemented
• Performance issue #691 - performance issue

[sxzz]

It appears a deadlock has occurred, causing the build to hang indefinitely. Can @rolldown/rolldown help me identify the cause?

• Happens on rolldown-plugin-dts
• Minimal tsdown config

import { defineConfig } from 'tsdown'

export default defineConfig({
  entry: ['src/index.ts', 'src/contract.ts', 'src/contracts/**/*.ts'],
  dts: {
    tsgo: true,
  },
})

• Install @typescript/native-preview, remove "src/contracts" form exclude of tsconfig.json
• Even the process is killed by Ctrl-C, there is still a running node process related to rolldown-binding.darwin-arm64.node.