X_BUILD_ENTRY_MISSING
Means
the build target's entry file is not in the app
Typical cause
an app scaffolded before x new wrote apps/web/server.ts and apps/web/prerender.ts, or one whose docker/Dockerfile was deleted — refused before the builder is spawned, because bun build's own "module not found" names no owner
Fix
the fix names the file; x new <name> --dry-run --json lists every entry a build needs