Bug tracking for Astro: session replay, console + HAR (2026)

Astro's pitch is "ship zero JavaScript by default", but the bugs your team will hit are not in the static HTML, they're at the **island boundaries**. A `<MyButton client:visible />` hydrates only when scrolled into view; a `<MyForm client:load />` hydrates on every page. Picking the wrong directive turns a 0-KB page into a 200-KB page, or a fast page into a janky one.

A useful Astro bug report needs the page route (static, server, hybrid?), the island component name + client directive, and what the user saw before AND after hydration. BugMojo captures both halves (the server-rendered HTML and the client takeover) in the same replay.

This guide covers Astro island hydration gotchas, view transitions bugs (Astro's native router), and the recommended BugMojo capture workflow for Astro teams in 2026.

Framework-specific failure modes engineers actually ship through. Each is hard to spot in a screenshot and obvious in a session replay.

Real Astro bug patterns: the symptom you will see in a report and the fix that actually works.

Island state resets on navigation with view transitions

Symptom: A persistent header with a search input loses its value when navigating between pages.

Fix: Add `transition:persist` on the element AND on the framework wrapper. View transitions only persist marked elements.

Environment variables undefined in client islands

Symptom: `import.meta.env.MY_KEY` is undefined when called from a hydrated island.

Fix: Astro env vars are scoped by prefix: `PUBLIC_*` are exposed to client, everything else is server-only. Rename to `PUBLIC_MY_KEY`.

Markdown component imports work in .md but not in .mdx

Symptom: `import` at the top of an MDX file fails to resolve.

Fix: MDX in Astro requires `@astrojs/mdx` integration AND component imports must be inside the frontmatter, not at the top of the file body.

The honest comparison: where BugMojo wins, and where another tool might serve you better.