`@babel/core` fails in all current variants

[MikeMcC399]

Situation

Running citgm @babel/core fails all tests
macos/ubuntu/windows
Node.js 22/24/26

Steps to reproduce

Run https://github.com/nodejs/citgm/actions/workflows/test-module.yml

Module to test: @babel/core
CITGM repository to checkout: nodejs/citgm
CITGM GitHub ref to checkout: main

Result

See https://github.com/MikeMcC399/citgm/actions/runs/34339097913

cc: @nicolo-ribaudo @JLHwung @liuxingbaoyu

[liuxingbaoyu]

Thank you for the reminder, I will look into it.

[liuxingbaoyu]

There appear to be multiple issues, but for some reason, citgm is testing v8.0.1, whereas the latest version is https://github.com/babel/babel/tree/v8.0.4.

[MikeMcC399]

https://www.npmjs.com/package/@babel/core?activeTab=versions shows that the npm registry has v8.0.1 as the latest published.

$ npm view @babel/core version
8.0.1

[liuxingbaoyu]

I see, Babel only publishes packages that have changed.
Can we have citgm always fetch the main branch?

[targos]

Yes, that can be done with "head": true in the lookup config.

[JLHwung]

The root cause of the failure is that browserslist is unhappy with the caniuse-lite provided in the repo snapshot of Babel v8.0.1.

I think this issue can be addressed in the CIGTM script.

Currently cigtm downloads

https://github.com/babel/babel/archive/v$(npm view @babel/core version).tar.gz

As a repo snapshot, the v8.0.1 contains an outdated yarn.lock, which browserslist is unhappy with. This is never an issue for our downstream npm consumers since the lockfile will not be published.

I recommend we implement the following two changes to the cigtm script:

1. Fetch the latest stable release version from github.com

Because Babel only publishes changed packages, there are chances that the latest @babel/core version, with the lockfile in the repo snapshot, does not work with latest Node.js. So we should fetch the latest version from github.com rather than npm registry. For example, the following command should print v8.0.4 as of September 9, 2026:

git ls-remote --tags --refs https://github.com/babel/babel.git | awk -F/ '{print $NF}' | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' | sort -V | tail -n1

Then we can supply the version to the downloader.

2. Set the BROWSERSLIST_IGNORE_OLD_DATA environment variable to 1 in the github workflow:

Per https://github.com/browserslist/browserslist/blob/f46a5b74e75fec2bda62c6520fc2296bda3c0fe3/node.js#L476, it disables the browserslist check.

---

As for head: true, I am afraid of noises from the HEAD, things might break especially during the time when Babel merges quite a few feature PRs before we do a minor release. If we set head: true chances are that an unreleased @babel/core might break the citgm. Most of time we will fix any conflict/errors after merging, but I don't feel it necessary to pop up the noise to here.