Maybe the pkg installer software looks to see if an installation is trying to mkdir in root and it automatically creates /etc/synthetic.conf with an entry. That would be quintessential Apple to do something like that. Thank you Apple, it just works.
On Fri, Jun 25, 2021 at 5:20 PM Ryan Schmidt <ryandes...@macports.org> wrote: > On Jun 25, 2021, at 21:03, Tabitha McNerney wrote: > > > On a fresh Catalina or Big Sure system, if you cd to root / then sudo > then try mkdir /opt or something else such as mkdir /hello the system won't > allow it, I get this: > > > > mkdir: /hello: Read-only file system > > > > note: the MacBook I just tried this on also has FileVault enabled and > its got one of those Apple T2 chips with a touch bar > > > > How does the MacPorts Catalina or Big Sur pkg installer work around this > restriction? > > I don't know that we're doing anything. It just works. > > There is some mechanism, that I don't understand, by which the system > volume and the data volume are combined into a single presentation. > Presumably the Installer app knows that you cannot install to the system > volume, so it installs MacPorts to the data volume. > >
