▶ This is a ${tag} prerelease build! Report issues here: h

Error message

▶ This is a ${tag} prerelease build!
  Report issues here: https://astro.build/issues

What it means

If the installed Astro version carries a prerelease tag (beta/alpha/rc/next), dev-server startup prints this notice asking you to report issues — you are running non-final code that may contain bugs. Purely informational; behavior is otherwise identical.

Source

Thrown at packages/astro/src/core/dev/dev.ts:150

	// Start listening to the port
	const devServerAddressInfo = await startContainer(restart.container);

	restart.bindCLIShortcuts();
	logger.info(
		'SKIP_FORMAT',
		msg.serverStart({
			startupTime: performance.now() - devStart,
			resolvedUrls: restart.container.viteServer.resolvedUrls || { local: [], network: [] },
			host: restart.container.settings.config.server.host,
			base: restart.container.settings.config.base,
			astroVersionProvider: new BuildTimeAstroVersionProvider(),
			textStyler: piccoloreTextStyler,
		}),
	);

	if (isPrerelease) {
		logger.warn('SKIP_FORMAT', msg.prerelease({ currentVersion }));
	}
	if (restart.container.viteServer.config.server?.fs?.strict === false) {
		logger.warn('SKIP_FORMAT', msg.fsStrictWarning());
	}

	logger.info(null, colors.green('watching for file changes...'));

	return {
		address: devServerAddressInfo,
		get resolvedUrls() {
			return restart.container.viteServer.resolvedUrls || { local: [], network: [] };
		},
		get watcher() {
			return restart.container.viteServer.watcher;
		},
		handle(req, res) {
			return restart.container.handle(req, res);
		},

View on GitHub (pinned to e294953aa8)

Solutions

If intentional, test away and report bugs at https://astro.build/issues
If unintentional, pin the latest stable: npm install astro@latest
Double-check package.json and lockfile for prerelease versions before deploying

Example fix

// before — package.json
"dependencies": { "astro": "^5.2.0-beta.3" }

// after — stable release
"dependencies": { "astro": "^5.2.0" }

Defensive patterns

Strategy: validation

Validate before calling

// CI: fail unless astro is a stable release
import { prerelease } from 'semver';
const v = pkg.dependencies.astro;
if (prerelease(v)) throw new Error(`Unexpected prerelease astro ${v}`);

Prevention

Lock and review package.json/lockfile before deploying so prerelease pins are intentional
Isolate beta testing in a branch with its own lockfile
Report bugs found on prereleases to keep the eventual stable release clean

When it happens

Trigger: The astro dependency in package.json resolves to a version like 5.2.0-beta.3, 5.0.0-rc.1, or 5.1.0-next.2 (isPrerelease computed from the running version).

Common situations: Beta-testing an upcoming major before upgrading; reproducing a regression on a canary; accidentally committing or deploying a prerelease pin.

Related errors

update ▶ New version of Astro available: ${latestVersion} Ru

AI-assisted analysis of withastro/astro@e294953aa8 (2026-08-18). Data as JSON: /api/errors/8e2d3c1e779db306. Report an issue: GitHub.