Netlify says "Build script returned non-zero exit code: 2" on my Bolt app. What now?

• The deploy log ends with Build script returned non-zero exit code: 2 and Failing build: Failed to build site (Netlify: Error reference).
• The app runs fine in Bolt's preview.
• Your latest changes never appear on the live site, or there's no live site at all if it never deployed.
• Publishing from Bolt to Netlify fails, or a GitHub-connected Netlify site fails after a push.

Netlify: "If you check your build log before the non-zero exit code, you can usually find more details about the reason for the failure." Its steps: go to Deploys, choose the failed deploy, open the build log, and scroll up to the failure (Netlify: Error reference).

The usual causes for Bolt apps:

1. TypeScript errors. Vite's dev server (what the preview runs) doesn't type-check. Vite's docs say it "only performs transpilation on .ts files and does NOT perform type checking" (Vite: Features). Many Vite TypeScript templates run tsc as part of npm run build, so type errors that never showed in the preview fail the build. Check your package.json build script.
2. Case-sensitive file names. Netlify's build file system is case-sensitive, and the error "may not clearly indicate this" (Netlify: Build troubleshooting tips). import Header from './header' fails if the file is Header.tsx. The log usually says Could not resolve or Cannot find module.
3. A different Node.js version. Netlify calls version mismatches "the leading cause of build failure" (Build troubleshooting tips).
4. Warnings treated as errors. Netlify sets CI=true, and some tools fail on warnings when they see it. Netlify suggests CI='' npm run build as the build command, and warns that CI=false "may not work as expected" (Build troubleshooting tips).
5. Missing environment variables or a wrong build setup. For Vite apps, Netlify's Bolt guide gives build command npm run build and publish directory dist (Netlify: Deploy your Bolt app).

1. Read the first real error

Open the failed deploy's log and scroll up from non-zero exit code to the first line with error, Error: or failed. Copy from there to the end. Netlify's error reference also mentions a Why did it fail? option on failed deploys that gives a diagnosis without using credits (Netlify: Error reference).

2. Reproduce the build in Bolt

In Bolt's terminal, run npm run build rather than the dev server. You'll usually see the same error. Bolt's docs mention running commands in Code view (Bolt: issues).

3. Fix by error type

4. Check build settings

For a Vite app: build command npm run build, publish directory dist (Netlify: Bolt guide).

5. Redeploy

Push the fix or republish from Bolt. If you duplicated or forked the Bolt project, Bolt's docs say you'll need to reconnect it to Netlify, which creates a new Netlify site (Bolt: Publishing issues).

Paste this into Lovable, Bolt, Cursor, Replit, v0 or whichever tool you build with:

My Netlify deploy fails with "Build script returned non-zero exit code: 2". Here is the build log from the first error to the end:
<PASTE LOG>
Fix only what this log reports:
1. Run `npm run build` (not the dev server) and fix every error it shows, including TypeScript errors. Don't remove type checking from the build script to hide them.
2. Make every import path match the real file name exactly, including capital letters.
3. If the Node version is the problem, add an .nvmrc with the Node major version this project needs.
4. List any environment variables the build needs so I can add them in Netlify.
Confirm `npm run build` succeeds before you finish, and list the files you changed.

1. npm run build succeeds in Bolt's terminal.
2. The next Netlify deploy shows Published.
3. Open the live URL in a private window and click through a few pages. If it builds but shows a blank page, see Bolt.new app blank white page on Netlify?

When a build fails, your fix simply never ships, and nothing on the live site tells you. Heedza checks your live landing, signup, login and checkout pages on a schedule and sends you a screenshot and a fix prompt if one stops loading or loses its form. It doesn't read your build logs or watch deploys. The free scan also checks whether files like /.env and /.git/config are publicly readable on your site.