Deploy Failed during stage 'building site1

Support
4

I set the node environment to the one I used on my local system.
That helped a bit. I have moved on to other errors now.

7:48:18 PM: [success] [webpackbar] Client: Compiled successfully in 7.71s
7:48:18 PM: wait Rendering static HTML...
7:48:18 PM: success Generated static files in src/.vuepress/dist.
7:48:18 PM: Done in 9.10s.
7:48:18 PM: ​
7:48:18 PM: (build.command completed in 9.2s)
7:48:18 PM: Build step duration: build.command completed in 9290ms
7:48:18 PM: ​
7:48:21 PM: Failed during stage 'building site': Build script returned non-zero exit code: 2 (https://ntl.fyi/exit-code-2)
7:48:21 PM: Build failed due to a user error: Build script returned non-zero exit code: 2
7:48:21 PM: Failing build: Failed to build site
7:48:22 PM: Finished processing build request in 37.49s

I set NETLIFY_BUILD_DEBUG to TRUE and changed my yarn command on package.json and the Netlify config from yarn build to yarn docs:build following advice from [Support Guide] Frequently encountered problems during builds but I can’t get it to build without an error.

My package.json contents (email changed) is:

{
  "name": "darty-docs",
  "version": "0.0.1",
  "description": "Documentation for Darty Ai",
  "main": "index.js",
  "authors": {
    "name": "Trevor",
    "email": "*****@******.com"
  },
  "repository": "/Darty-Docs",
  "scripts": {
    "dev": "vuepress dev src",
    "docs:build": "vuepress build src",
    "b": "vuepress build src",
    "bd": "vuepress build src && vuepress dev src",
    "index": "node -e \"require('../build-code/test-script.js').default()\""
  },
  "license": "MIT",
  "devDependencies": {
    "vuepress": "^1.5.3",
    "vuepress-plugin-fulltext-search": "^2.2.1"
  },
  "dependencies": {
    "@vuepress/plugin-back-to-top": "^1.9.9",
    "@vuepress/plugin-medium-zoom": "^1.9.9"
  }
}

The build is Netlify App

Please can you give me some more guidance?