You upgraded to a shiny new M1 Mac (MacBook, MacBook Pro or Mac Mini) but now brew is broken on your new ARM machine. You can easily fix this:

Depending if you use zsh or bash you need to put the following in either ~/.zshrc or ~/.bashrc :

alias brew='arch -x86_64 brew'

If you haven’t installed Rosetta 2 on your machine yet, you will automatically get an installation prompt the first time you run brew.

This will emulate brew (for now) using Rosetta 2 until brew officially supports ARM on Mac.



You just upgraded your brew packages and composer updated itself to version 2.x but you still need version 1.x? This is how you can downgrade (& upgrade again):

Show available versions of composer:

brew log composer

For me the latest 1.x version to date is: composer 1.10.15

Let’s downgrade

composer self-update 1.10.15

To switch back to the 2.x version use

composer self-update --rollback



If vagrant does not run on macOS 11 Big Sur and you’re not able to update it’s plugins, follow this guide.


If you use brew for ansible etc. Make sure brew works under Big Sur:

Update vagrant

First make sure you have the latest version of vagrant.
Download the latest version from:

Let’s update the vagrant plugins

vagrant plugin update

You should get a message like

Updated 'vagrant-share' to version '1.1.11'!
Updated 'vagrant-vbguest' to version '0.28.0'!

Now try it again.

vagrant up

It now should work just fine.



Sascha Eggenberger

Sascha Eggenberger

Sascha Eggenberger. Senior Product Designer @GitLab. Drupal Core Maintainer. Drupal Design System, Claro, Gin. #OpenSource