Composer 2 has been released with several great features and improvements! Best of all it's (mostly) backward-compatible with Composer 1. The one issue you're most likely to encounter when upgrading to Composer 2 is having Composer plugins that don't support this newer version yet.
The ideal solution would be upgrading those plugins to newer versions (or submitting a feature request to the plugin developers to support Composer 2). But if that's not feasible you can actually co-install both Composer 1 and Composer 2 by following these steps:
Step 1: Install Composer 1 separately
Assuming you already have Composer installed, this will create a copy of it called composer1:
sudo cp `which composer` /usr/local/bin/composer1 && sudo composer1 self-update --1
Step 2: Upgrade Composer to v2
If you haven't already upgraded your main composer program to v2 you can do so with this command:
composer self-update --2 # You might need to run this with "sudo"
At this point, you'll have two commands available on your machine:
composer- The latest version of Composer (v2)composer1- A separate copy of Composer (v1)
Step 3: Add composer2 alias (optional)
If you'd also like to have composer2 available as a command, simply create the following symlink:
sudo ln -s `which composer` /usr/local/bin/composer2
Now you have three commands at your disposal:
composer- The latest version of Composer (v2)composer1- A separate copy of Composer (v1)composer2- A symlink tocomposer