Node v25 with git Last Modified Performance Issues

[craigerskine]

Operating system

macOS Tahoe 26.1

Eleventy

3.1.2

Describe the bug

I just updated to node v25.1.0 and one of my sites is taking over 15s to build. It normally builds in about 0.18s. I tracked it down to this:

11tydata.json:

{
  "date": "git Last Modified"
}

If I downgrade node to v20.X the site builds in 3s.

Reproduction Source Code URL

https://github.com/craigerskine/cmx.media

Screenshots

No response

[zachleat]

That feature is slow. How many templates does it apply to?

That said, I do see some difference locally on eleventy-base-blog (scoped to 5 template files using a directory data file) between Node 20 and some slowness introduced in Node 22:

Node 20.19.3:
Copied 2 Wrote 16 files in 0.18 seconds (v3.1.2)

Node 22.21.1:
Copied 2 Wrote 16 files in 0.48 seconds (v3.1.2)

Node 24.11.1:
Copied 2 Wrote 16 files in 0.47 seconds (v3.1.2)

Node 25.2.0:
Copied 2 Wrote 16 files in 0.47 seconds (v3.1.2)

[zachleat]

Related #3959 #3912

[zachleat]

This uses import { spawn } from "node:child_process"; under the hood, if there is some Node variability between versions there!

Link to our code:

eleventy/src/Util/Git.js

Line 1 in a9ee377

import { spawnAsync } from "./spawn.js";

[craigerskine]

That feature is slow. How many templates does it apply to?

That said, I do see some difference locally on eleventy-base-blog (scoped to 5 template files using a directory data file) between Node 20 and some slowness introduced in Node 22:

Node 20.19.3:
Copied 2 Wrote 16 files in 0.18 seconds (v3.1.2)

Node 22.21.1:
Copied 2 Wrote 16 files in 0.48 seconds (v3.1.2)

Node 24.11.1:
Copied 2 Wrote 16 files in 0.47 seconds (v3.1.2)

Node 25.2.0:
Copied 2 Wrote 16 files in 0.47 seconds (v3.1.2)

341 Templates.

I want to automate a list of the 6 newest entries without me having to manually add a date frontmatter. I tried all the other date options but when the site is deployed at Netlify git Last Modified is the only thing that really works.