MacPorts and /opt/local on Catalina and Big Sur read only volumes

[Ryan Schmidt]

On Jun 25, 2021, at 18:07, Tabitha McNerney wrote:

> Hi all,
> 
> I haven't installed a fresh MacPorts system in quite some time but will soon be doing so on a few Macs one running Catalina and the other Big Sur. Starting with Catalina, the root volume / is read-only so how do the MacPorts package installers set things up such that /opt/local can remain the default path to MacPorts for both read and write functionality on Catalina and Big Sur? Do the MacPorts package installers make use of Apple's new bi-directional firmlinks capability defined in /etc/synthetic.conf as also described on this page? 
> 
> https://derflounder.wordpress.com/2020/01/18/creating-root-level-directories-and-symbolic-links-on-macos-catalina/
> 
> Thank you.

I'm not aware of MacPorts doing anything special for this. It just works?