[Scons-users] Compiling with Scons on Mac arm64

[Mats Wichmann]

On 2/2/22 10:56, Mats Wichmann wrote:
> On 2/1/22 10:36, Paola Ferrario wrote:
>> Hi all!
>> I’m having a problem compiling my C++ application using Scons on a Mac
>> with M1 processor. 
>> Specifically, it seems that it tries to compile for a x86_64
>> architecture, since I see a lot of warnings such as 
>> "warning: ignoring file ..., building for macOS-x86_64 but attempting to
>> link with file built for macOS-arm64”
>> when linking to third-party libraries, correctly compiled in the arm64
>> architecture. After the warnings, the compilation ends with error 
>> “ld: symbol(s) not found for architecture x86_64”
>>
>> I was wondering if there is a flag I can pass to the compiler to specify
>> the architecture. I’ve tried with 
>>
>> -arch=arm64
>>
>> but it doesn’t work.
>> What should I do?

You checked in objects in your toy, and they show this:

source/nexus.o:                              Mach-O 64-bit x86_64
object, flags:<|SUBSECTIONS_VIA_SYMBOLS>

so the build is somehow targeting x86_64.  Any chance you can show a log
of the build?  I don't have an M1 Mac available - I think Bill does though.


Also this:

    p = subprocess.Popen(cmd, shell=True,
                         stdout=subprocess.PIPE,
                         stderr=subprocess.PIPE)

    ## If the stdout is empty, the execution of the command failed
    version = p.stdout.read()
    if version == '':
        Abort("Failed to establish Geant4 version.")


subprocess, unless told otherwise, will sent back bytes, so to be valid
that comparison needs to be:

if version == b"":

for the other branch it's decoded, so that's fine.