Composer still installing Sage 8.5.3

Following the install instructions at https://roots.io/sage/docs/theme-installation/ still results in composer downloading Sage 8.5.3. I have run composer clear-cache to make sure I have cleared the cache for previous versions.

Reading through https://getcomposer.org/doc/03-cli.md#create-project, it looks like I can specify a minimum version of the project using some flags, but this may be something the team wants to update so that it installs Sage 9 by default instead of the older Sage 8.5.3.

It looks like this may have been a PHP version issue; my local OS host is running PHP 5.6.3, whereas my VM is running 7.1. Was running Composer from the host OS instead of in the VM. Am testing further to verify.

As noted in my original post, I have already run this.

It looks like the root cause of the issue was not having PHP 7.x on my host OS. I was able to successfully install it in the VM without issue. Marking resolved.