I don't know all of the brew lingo, but I think using the cask option/command uses the DMG. That's what I use when I saw that message a while ago
LibreWolf
Welcome to the official community for LibreWolf.
LibreWolf is designed to increase protection against tracking and fingerprinting techniques, while also including a few security improvements. LibreWolf also aims to remove all the telemetry, data collection and annoyances, as well as disabling anti-freedom features like DRM. If you have any question please visit our FAQ first: https://librewolf.net/docs/faq/
To learn more or to download the browser visit the website: https://librewolf.net/
If you want to contribute head over to our Codeberg: https://codeberg.org/librewolf
The commit says something about something being “unsigned.” I suspect that means the LibreWolf artifact is unsigned, so they can’t verify its integrity.
https://github.com/Homebrew/homebrew-cask/pull/221666/files#diff-a2f494476a9a3132aa0da63b28d9fa05eb7180e78c32148864c7cdc214df33b9R22
The same thing just happened to Chromium:
https://github.com/Homebrew/homebrew-cask/pull/221570/files#diff-7073d00a063da1cbaa54537a0299fc88c89e55c6a7a0e0de2c34e82752d90e3aR13
Edit to add: Perhaps this was done in error, and perhaps it’s related to this issue: Autobump restrictions make opening PRs with bump-cask-pr overly complicated
The way to keep it in homebrew is to either start signing librewolf builds or provide an alternative tap from Librewolf's repo. One of the catalysts for the deprecation is that installing unsigned apps seems to only work in Intel-based macs and Apple has decided macOS 26 will be the last release that will support this architecture.
For months (years?) I’ve been installing it on ARM-based Macs by using brew install --no-quarantine
.
The --no-quarantine flag might be deprecated. There's a discussion on homebrew github about disabling it, as Apple is closing the door on unsigned apps: https://github.com/Homebrew/homebrew-cask/issues/170345#issuecomment-2030021717