fix for libtheora to build on 10.6.8 Rosetta

[barracuda156]

libtheora fails to build for ppc on 10.6.8 Rosetta, however this simple fix works:

if {${os.major} == 10 && ${build_arch} eq "ppc"} {
configure.args-append --build=powerpc-apple-darwin10 \
                      --host=powerpc-apple-darwin10
   }

[ryandesign (Ryan Carsten Schmidt)]

In what way does it fail to build? It would be surprising to me if whatever failure you encountered uniquely only occurred on 10.6.8 when building for ppc. It seems more likely to me that it would occur on a broader range of systems: for example, perhaps it occurs any OS version when building for a non-default architecture. But I won't know without seeing your main.log.

[ryandesign (Ryan Carsten Schmidt)]

--build is supposed to reflect the machine doing the building while --host is supposed to reflect the machine on which the compiled program will ultimately run. As such, if you are building on an Intel Mac (as I assume you are based on the mention of Rosetta) then --build=powerpc-apple-darwin10 does not seem correct.

I also don't think your proposal correctly handles the universal variant. If this build system needs --build / --host flags, then it will most likely need different flags for each architecture in a universal build, which means using the muniversal portgroup. The muniversal portgroup already contains code that can set --build and --host flags for you, but regrettably only when the universal variant is selected; it is left up to the portfile author to set them correctly when the universal variant is not selected.

[barracuda156]

Log of errors, there are many

[barracuda156]

Building successfully after the fix

[barracuda156]

Replying to ryandesign:

--build is supposed to reflect the machine doing the building while --host is supposed to reflect the machine on which the compiled program will ultimately run. As such, if you are building on an Intel Mac (as I assume you are based on the mention of Rosetta) then --build=powerpc-apple-darwin10 does not seem correct.

It is correct because I build it natively as ppc32 using Rosetta.

Sergey-Fedorovs-Mac-mini:~ svacchanda$ port -v installed libtheora
The following ports are currently installed:
  libtheora @1.1.1_3 (active) requested_variants='' platform='darwin 10' archs='ppc' date='2022-02-04T22:53:59+0800'

While many ports still do build for ppc on 10.6.8 with incorrect --build set for Intel, a number of ports fail with it. None has been failing so far because of --build=powerpc-apple-darwin10.

[kencu (Ken)]

For MacPorts to accept a fix into either base or into a Portfile, it generally has to be what you would call a "pure, true fix". Anything else is, in the long run, going to be more trouble than it is worth.

[barracuda156]

Replying to kencu:

For MacPorts to accept a fix into either base or into a Portfile, it generally has to be what you would call a "pure, true fix". Anything else is, in the long run, going to be more trouble than it is worth.

Sorry, could you please elaborate a bit? (I am aware that building on 10.6.8 for ppc is an exotic endeavor, but as long as it doesn’t interfere with anything else, why not add?)

[Wowfunhappy (Jonathan)]

How are you actually running MacPorts under Rosetta? Are you just prefacing every command with /usr/bin/arch -arch ppc? I tried that, and it didn't seem like all subprocesses were actually going through Rosetta as I needed.

It would be nice if e.g. on Leopard, I could use Rosetta to create PPC binaries even though I don't have access to PPC hardware. This seems like something that should "just work" in theory.

[kencu (Ken)]

I haven't tried it, Jonathan, but others have noticed that MacPorts follows the arch of the terminal.

SO it might happen that if you opened a terminal on 10.5 Intel in PPC arch, MacPorts would follow that. Some experimentation required, your mileage may vary, etc, etc.

[kencu (Ken)]

You can build PPC software quite easily on 10.4 and 10.5 Intel, in general.

MacPorts has never enabled cross-arch building with gcc, because newer gcc versions don't support the easy "multi-arch" command line settings that make that simple, and building cross-arch otherwise requires quite a bit of shenanigans.

Some are working on this! See here:

​https://github.com/iains/darwin-toolchains-start-here/discussions/13

[barracuda156]

Replying to Wowfunhappy:

How are you actually running MacPorts under Rosetta? Are you just prefacing every command with /usr/bin/arch -arch ppc? I tried that, and it didn't seem like all subprocesses were actually going through Rosetta as I needed.

I have built Macports itself as ppc (passing --build=powerpc-apple-darwin10 and -arch ppc -m32 flags to configure) on 10.6.8 and set ppc as the build arch in Macports.conf. From what I see in Activity Monitor, most processes do in fact run as PowerPC. Some OS binaries lack ppc slices (say, ld and gnumake), but they support building for ppc.

So for example I have:

Sergey-Fedorovs-Mac-mini:~ svacchanda$ file /opt/local/libexec/macports/lib/macports1.0/MacPorts.dylib 
/opt/local/libexec/macports/lib/macports1.0/MacPorts.dylib: Mach-O dynamically linked shared library ppc
Sergey-Fedorovs-Mac-mini:~ svacchanda$ file /opt/local/libexec/macports/bin/tclsh8.5 
/opt/local/libexec/macports/bin/tclsh8.5: Mach-O executable ppc

Sergey-Fedorovs-Mac-mini:~ svacchanda$ sw_vers
ProductName:	Mac OS X
ProductVersion:	10.6.8
BuildVersion:	10K549

[barracuda156]

In fact only --build=power-apple-darwin10 is enough for Rosetta to work: ​https://github.com/macports/macports-ports/pull/15580

[barracuda156]

In f70687997a022399a5f0f630086b3f3d4c1bc850/macports-ports (master):

libtheora: fix build on Rosetta
Fixes: #64607