ci: don't fail preview builds on broken internal links

.github/workflows/cloudflare-preview-forks-build.yml

@@ -78,10 +78,12 @@ jobs:
       - name: Install dependencies
         run: npm ci
 
-      # textlint and prettier run in test.yml. They are left out here so a
-      # wording or formatting problem doesn't hold back the preview.
+      # textlint, prettier, and failing on broken links run in test.yml. They
+      # are left out here so those problems don't hold back the preview.
       - name: Build
         run: npm run build
+        env:
+          PREVIEW_BUILD: "true"
 
       - name: Save PR number
         run: echo "${{ github.event.pull_request.number }}" > dist/pr-number.txt

astro.config.mjs

@@ -77,7 +77,12 @@ export default defineConfig({
     prefetch(),
     linkValidator({
       checkExternal: false,
-      failOnBrokenLinks: true,
+      // Previews report broken links without failing, like textlint and
+      // prettier; the build in test.yml is the check that fails.
+      failOnBrokenLinks: !(
+        process.env.PREVIEW_BUILD ||
+        (process.env.CF_PAGES && process.env.CF_PAGES_BRANCH !== "main")
+      ),
       exclude: ["/_astro/*", "/s/*", "/board", "/download/*"],
     }),
   ],