Astro 7.3 shipped a few days ago. Most of the attention is probably going to the bigger stuff, but there's a one-line change in the CLI that I think is more useful day-to-day than it looks: astro preview finally got an --ignore-lock flag.
Some background first
Astro 7.0 introduced a lockfile for astro dev — every time you start a dev server, Astro writes a small file recording its URL, port, and PID, specifically so AI coding agents don't accidentally spin up duplicate dev servers for the same project while you're already running one.
Reasonable problem to solve. But it had a side effect: if you wanted to run a second dev server on purpose — say, a throwaway instance with verbose logging while your main one keeps running — Astro would just error out. The lockfile didn't know the difference between "an agent accidentally duplicating" and "a human doing this deliberately."
Astro 7.1 fixed that for astro dev with --ignore-lock, which skips the lockfile check entirely so a second instance can run alongside the first. Astro 7.2 then added the same lockfile protection to astro preview — but forgot the escape hatch. So you'd hit the exact same wall, just one command later.
Astro 7.3 closes that gap:
astro preview --ignore-lock
Why this specifically matters for testing
The Astro team calls out the actual use case in their own release notes: Playwright and other E2E testing workflows that need multiple preview servers running at once.
If you've set up playwright.config.ts with a webServer block (the way most Astro + Playwright setups do it), the test runner spins up its own preview server automatically. If you're also running your own preview server locally — to manually poke at the same build, or running two suites against two different ports — you'd hit the lock before 7.3, full stop.
I just went through setting up a Playwright suite for a recent project, and this is exactly the kind of small friction that doesn't show up until you're mid-debug and confused about why your test runner won't start. Nice to see it closed less than a year after the original lockfile shipped.
Small feature, but worth knowing
Nothing here changes how you build a site. It's the kind of change that's easy to skim past in a changelog and then rediscover the hard way three months later when you actually need it. If you're running Playwright against an Astro project, it's worth having this in the back of your mind before it becomes a "why is this broken" moment instead of a one-line fix.
Written at 3am, fueled by coffee and questionable life choices ☕
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