mozilla/gecko-dev ? reverse-engineered prompt

I want to get this Firefox source code building and running locally on my machine.

Please inspect the repo, figure out the right setup steps, and make sure I can produce a working browser build from source. If there are any missing pieces, outdated instructions, or environment issues, fix them or clearly point them out. I’d also like a simple way to launch the browser after the build so I can verify it worked.

If you need current setup details or docs, look them up online and use the official Firefox source docs when needed. Keep the changes minimal and practical, and update the README or add a short note with the exact steps I should follow if that helps.