On Aug 19, 2023, at 09:12, Andreas Falkenhahn wrote:
> I've installed MacPorts on a macOS 13 system but I'd like to build programs
> that run on all systems that have at least macOS 11. That's why I run gcc
> with the -mmacosx-version-min=11.0 argument. This, however, leads to warnings
> of the following kind during linking:
>
>ld: warning: dylib (/opt/local/lib/libfreetype.dylib) was built for newer
> macOS version (13.0) than being linked (11.0)
>...more similar warnings for other dylibs installed by MacPorts...
This is happening because /opt/local/lib/libfreetype.dylib was not built with
the deployment target you wanted, either because you built it from source
without having specified that you wanted the macOS 11.0 deployment target or
because you received our Ventura binaries which were built for the macOS 13.0
deployment target.
> Is there any way to install the dylibs for macOS 11.0 on a macOS 13 system
Within MacPorts, there is not.
> or how am I supposed to build MacPorts programs on macOS 13 that run on older
> macOS versions as well?
If this is your goal, then you would edit macports.conf and set
"macosx_deployment_target 11.0". If you also want to use the macOS 11 SDK as
someone suggested, you would additionally set "macosx_sdk_version 11". There is
no macOS 11 SDK on Ventura so you would also have to acquire that SDK (either
manually from an earlier version of Xcode or the command line tools, or by
installing the MacOSX11.sdk port) and put it in the right place.
These macports.conf options are undocumented and while they are supposed to
work, not many people use them, so you may run into a fair number of ports that
don't support them properly. If you find such ports, those would be bugs that
ideally should be fixed, but it usually stems from build systems that are going
out of their way to force their own deployment target or SDK selections so it
can take a bit of work to convince those build systems not to do that.
You would also have to set "buildfromsource always" to prevent getting our
binaries. If you already installed any ports, you should probably uninstall
them and then reinstall them so they get built for your desired deployment
target.
You may want to use a MacPorts prefix other than /opt/local for these
activities. By doing that, you'll automatically build from source since our
binaries are only used when the prefix is /opt/local. You'll also want to
change the applications dir (for example to an Applications directory inside
your prefix) and disable startup items. These settings leave open the option of
having a normal MacPorts prefix at /opt/local for when you just want to install
something quickly (using our binaries) for the current macOS.
I agree with the other responders who said it is easier to build on the OS
version you're targeting. That's what we do for our buildbot workers (one
worker per OS version). If your machine supports booting to macOS 11, you can
install it on a separate volume and boot to it when needed. If it doesn't, or
if rebooting is inconvenient, you could set up a virtual machine (with VMware
Fusion, VirtualBox, Parallels Desktop, etc.) to run a macOS 11 environment
within your current macOS version.
