SvelteKit

SvelteKit’s CHANGELOG.md in the packages/kit directory is the operational known-issues surface. Breaking changes appear inline with each version entry rather than in a separate migration guide, which means the changelog is the first file to open when an upgrade fails.

The routing overhaul that replaced __layout.svelte and __error.svelte with +layout.svelte and +error.svelte is the canonical example of how SvelteKit announces structural changes: a clear entry, a migration note, no codemod. Teams that skip several versions at once accumulate these entries; reading the changelog linearly from the last pinned version is the only reliable way to reconstruct what broke and in what order.