macosx_deployment_target - building for previous versions from MacOS 10.13

[Ryan Schmidt]

> On Sep 4, 2020, at 06:14, Jeffrey Walton wrote:
> 
> On Fri, Sep 4, 2020 at 6:54 AM Friedrich Beckmann wrote:
>> 
>> ...
>> I just figured out that ncurses indeed does not build for deployment target 10.5 because macports or whoever sets the CXXFLAGS to
> 
> Sorry to hear this. Ncurses is a mess. I cringe when it is needed...
> No source code repo, bizarre processes and procedures, memory leaks
> out the ass, ...
> 
> Are you fetching their patches per
> https://invisible-island.net/ncurses/ncurses.faq.html#applying_patches?
> 
>> :debug:configure CXXFLAGS='-pipe -Os -stdlib=libc++ -arch x86_64 -arch i386‘
> 
> Be careful of this. It assumes all packages are fat/universal safe.

No, it assumes *this* port can be built this way, based on the evidence we have gathered thus far. Each port can make its own choices.

> That is not the case. For example, OpenSSL is not fat safe because of
> different configuration files depending on the platform, and the way
> it wields the AR command.
> 
> You need to do something like https://stackoverflow.com/q/25530429.
> You build the library for each platform, rig up some header files, and
> use lipo to combine your output artifacts.

And for that reason, the openssl port already specifies that it needs the muniversal portgroup, which is our method of building for each arch separately and lipoing the results together.