> On Jan 11, 2021, at 9:07 PM, Ryan Schmidt <ryandes...@macports.org> wrote: > On Jan 11, 2021, at 19:38, Craig Treleaven wrote: > >> A user with a new Apple Silicon-based Mac had a go at building mythtv.28. >> It failed thusly: >> >> ---> Computing dependencies for mythtv.28 >> Error: Cannot install mythtv-core.28 for the arch 'x86_64' because >> Error: its dependency logrotate does not build for the required arch by >> default >> >> https://trac.macports.org/ticket/62027 >> >> Given Rosetta2 on these systems, isn’t this a bogus error? On M1 Macs, we >> might warn that a dependency is being built for an arch different from that >> of the main target but why should it be a fatal error? >> >> What was done during the PPC to Intel transition? Did we try to force all >> deps of a port to build with the same arch? > > MacPorts 2.6.4 is supposed to support all possible arch demotions. On arm64, > you're supposed to be able to run x86_64. On x86_64, you're supposed to be > able to run i386. On i386, you're supposed to be able to run ppc. Some of > this was already in place before, and it was enhanced for 2.6.4 in this > commit: > > https://github.com/macports/macports-base/commit/94f428eda6bd58b57c670c20fb2362ad7012310a > > See this ticket: > > https://trac.macports.org/ticket/61430 > > Installing a port for a demoted architecture would require its dependencies > to be installed universal. MacPorts is trying to install the dependencies > universal and is failing on logrotate because it does not have a universal > variant. The solution is to add a universal variant to logrotate. > Alternately, if logrotate does not install any libraries (and it looks like > it does not), add "installs_libs no" to the logrotate portfile so that > MacPorts knows it does not need to check its architecture. Or if logrotate > does install libraries but whichever one of mythtv.28's dependencies depends > on logrotate (looks like it's mythtv-core.28) doesn't link with any of its > libraries, add "depends_skip_archcheck logrotate" to mythtv-core.28. >
Am I incorrect that Rosetta2 does NOT require library dependencies to be the same arch as the main program? I thought I understood that an X86_64 program could call an arm64 library (and vice versa) and that Rosetta2 would do the right thing at run time. If so, MacPorts does not have to supply a mult-arch/universal library. I understand that Rosetta2 is not going to around forever—maybe 2 to 5 years. However, if it does automatically translate libraries at run time, that would permit quite a number of ports to work immediately. No? Craig
