How to specify target architecture (x86_64 or arm/native) when building qmake project on M1?

Violet Giraffe · 14 Mar 2023, 12:56

I have a problem with one of my projects, and can't understand why it happens. When built on M1 Mac system, some targets are compiled for x86_64 and some for arm64. Naturally, I get a linker error for arch mismatch. How to specify the desired architecture with qmake and Qt 5.15.2?

I have other C++ projects that build fine with the same Qt version on the same system.

Violet Giraffe · wrote on 14 Mar 2023, 22:59

Found it! The required compiler flag is -arch x86_64

jsulm · 14 Mar 2023, 12:57

@Violet-Giraffe said in How to specify target architecture (x86_64 or arm/native) when building qmake project on M1?:

How to specify the desired architecture with qmake and Qt 5.15.2?

By calling qmake from Qt for that architecture.

Violet Giraffe · 14 Mar 2023, 20:10

@jsulm, I already do, this is Qt 5.15.2 clang_64 (and 5.15.2 only exists for x86_64 on Mac, I believe).

SGaist · 14 Mar 2023, 21:50

@Violet-Giraffe hi,

Your other project likely uses libraries that are universal, meaning that they embed both x86_64 and arm64 symbols.

From memory, Qt 5.15.2 is single arch so you would need to build it yourself for the M1.

Violet Giraffe · 14 Mar 2023, 22:59

@SGaist, hi, thanks for chiming in! Let me clarify and expand on the question.

I do not want to build for M1/ARM, I only want a pure x86_64 build. So it's no problem that Qt 5.15.2 doesn't support M1.
Some of my own libraries, built by this project, were compiled for M1, and some others for x86_64. It's not even that my M1 binaries cannot be linked with x64 Qt - no, parts of my own project and my own code are being built inconsistently.
The other project is also a C++ qmake subdirs project that uses Qt 5.15.2 and it builds fine, but that didn't help me to figure out why or what the problem is.

So in short - I don't want to target M1, I want to stop it from targeting M1 and force x86_64 instead.

Violet Giraffe · wrote on 14 Mar 2023, 22:59

Found it! The required compiler flag is -arch x86_64

Mehrshad · 27 Jul 2023, 05:31

Excuse me, but I'm still having a similar problem. I did as you said, and ran ./qmake -set arch x86_64, but nothing changed in action. Could you state more specifically what you did to get it fixed?

More details:
I'm on an Intel Mac running macOS 12.6.8 and Xcode 14.2. The thing is, I had been using Qt 6.4.2 and Qt Creator 10.0.2, but after a series of Qt-related upgrades, I eventually ended up with Qt 6.5.2 and Qt Creator 11.0.0. Right now, Qt Creator cannot identify any Qt-related classes or identifiers, and I'm getting the same error as you did under Preferences, Kits, Qt Versions. However, projects are being built using the play button.

jsulm · 27 Jul 2023, 08:12

@Mehrshad said in How to specify target architecture (x86_64 or arm/native) when building qmake project on M1?:

and I'm getting the same error as you did under Preferences, Kits, Qt Versions

What error is that?
What exact Qt version did you install?

Mehrshad · J jsulm 27 Jul 2023, 05:31

@jsulm I'm sorry. I realize I had replied on the wrong topic. I posted an all-new topic here. I would be more than glad if you could check it out and tell me what you think.

Violet Giraffe · wrote on 28 Sept 2023, 14:17

For Qt 6.5.3:

QMAKE_APPLE_DEVICE_ARCHS = x86_64

or QMAKE_APPLE_DEVICE_ARCHS = x86_64 arm64 to create a universal binary, but I have not tested that.

Austin K · 4 Aug 2024, 08:36

After creating a 64 bit arm64 binary for m1 on OSX Im getting an error with macdeployqt:

mach-o file, but is an incompatible architecture (have 'x86_64', need 'arm64e' or 'arm64')

(mach-o file, but is an incompatible architecture (have 'x86_64', need 'arm64e' or 'arm64')), '~/build/arm64/myapp/Contents/MacOS/QtQuickControls2.framework/Versions/5/QtQuickControls2' (no such file), '~build/arm64/myapp/Contents/Frameworks/QtQuickControls2.framework/Versions/5/QtQuickControls

When I look at the actual app it is a 64 bit arm app.

Using Qt 5.15.17 - latest and greatest.

When running the application in Qt Creator it runs fine. macdeployqt is not creating a correct binary for arm64. However it works fine for x86_64.

SGaist · wrote on 4 Aug 2024, 08:36

@Austin-K hi and welcome to devnet,

AFAIK 5.15.17 is currently a commercial only release so you should check with the Qt Company what is happening with macdeployqt.

Austin K · 8 Oct 2024, 20:01

@SGaist to I actually was able to fix this.

I had to ensure I was using the arm 64-bit version of macdeployqt contained in /macos/

~/Qt5.15.17/5.15.17/clang_64/bin/macdeployqt
~/Qt5.15.17/5.15.17/macos/bin/macdeployqt

Its important to use the correct one for the architecture you are building for.

Thank you.