Installation fails on M4/Sequoia but Coordinator and SystemExtensions still there

Avast Mac Security
1

I’ve tried to install Avast’s free security for MacOS about 15 times on an M4 Mac and it’s failed every time. Initially I thought it was because I had used Apple’s Migration Assistant to copy everything over from my old Intel-based Mac (which was running Monterey), but I used sudo find / -iname '*avast*' -ls and think I got rid of everything from it.

I’m using the latest avast_security_online installer downloaded from the “Free antivirus for Mac” page.

The installation gets as far as the final “Verifying…” step then fails and appears to uninstall everything. Except the Avast Coordinator app is still in my “Login Items and Extensions” in Settings, and /Users/<me>/Library/Containers/com.avast.Antivirus.SystemExtension remains on disk and can’t be removed even with sudo.

Restarting and retrying the installation doesn’t work.

I’ve managed to save the install logs from the tmp dir but nothing stands out as an obvious cause of failure.

2

Ah, I figured it out. I still had my default shell as /usr/local/bin/bash, which was the x86 bash installed via Homebrew on the old Intel MacBook then migrated over. Running chsh -s /bin/zsh (as Apple often nags us bash rebels to) then reinstalling fixed it.

Some of the installation steps ran scripts using my default login shell, and they couldn’t.