vercel/ncc

Regression: dynamic runtime `require` works in 0.38.1 but breaks in 0.38.2

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#1312 opened on Mar 16, 2026

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 (2 comments) (0 reactions) (0 assignees)JavaScript (8,841 stars) (273 forks)batch import
help wanted

Description

0.38.1

I have the following source code:

https://github.com/CatChen/eslint-suggestion-action/blob/930479a34a06bfa384291cc877f9d1ce21533ae1/src/getESLint.ts#L16-L19

The dynamic require is compiled into the following code:

https://github.com/CatChen/eslint-suggestion-action/blob/930479a34a06bfa384291cc877f9d1ce21533ae1/bundle/index.js#L37587

0.38.2

The same code is compiled into the following code since 0.38.2:

https://github.com/CatChen/eslint-suggestion-action/blob/bc0de7fa625de9daf56cca84b6084f4d6bcbaca4/bundle/index.js#L37702

Workaround

My current workaround is to use dynamic import inside a new Function() (because dynamic import isn't supported either). I have to change to code into this:

https://github.com/CatChen/eslint-suggestion-action/blob/927208b2e684b1a7c721f4a0e70d4f4e8c11c228/src/getESLint.ts#L15-L26

Contributor guide

Tech stack
nodejsjavascripttypescript
Domain
toolingbuild systemdeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
basic Node.js module systemfamiliarity with ncc
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
25
Research direction
Examine the changes between ncc 0.38.1 and 0.38.2, focusing on the bundling logic for dynamic require statements. Look at the generated code differences and identify the commit that introduced the regression. Consider if the issue is related to changes in how require is transformed or if it's a broader problem with dynamic imports. Check the repository's issue tracker for related discussions or pull requests.