Cross compiling from Linux to Android

I am trying to build an Android project from Linux. I am getting the following message from conan package tools.

Page       :  1
Builds list:
[('settings', {'os': 'Android', 'os.api_level': 24, 'arch': 'x86', 'build_type': 'Debug', 'compiler': 'clang', 'compiler.version': '5.0', 'compiler.libcxx': 'libc++'}), ('options', {}), ('env_vars', {}), ('build_requires', {})]

############## CONAN PACKAGE TOOLS ######################

DEBUG: - Skipped build, compiler mismatch: {'arch': 'x86', 'build_type': 'Debug', 'compiler': 'clang', 'compiler.libcxx': 'libc++', 'compiler.version': '5.0', 'os': 'Android', 'os.api_level': '24'}

#########################################################

If I run

• conan create orhun/testing -s os=Android -s os.api_level=24 ... directly it works.
• If I remove relevant code from _run_test_package in test_package_runner.py, it works.

Is the check in _run_test_package in error or am I missing something?

Thanks.

[orhun-sketchup]

It’s an old check that I think can be deleted because of the latest package tools improvements, but we should check it carefully before removing it.

That’s why I was thinking I was missing something. I generally work on windows and I didn’t hit this check previously because it skips the check on windows.

I think the check at least should verify we are cross building or not (i.e. check whether default_profile["os"] == settings.get("os") ). In my case default_profile["os"] is Linux but settings.get("os") is Android.

At that point I think conan-package-tools could assume user have set their cross build environment correctly. Basically _detected_compiler_override is too early if I am setting CC and CXX through conan package dependencies.

Note: I just noticed what _detected_compiler_override does. If I had noticed it earlier, I would have just set these variables in my ‘build.py’ for my cross compiles to something else. They don’t even have to be correct, since conan will set them for me later, during the actual build. See below.

But how is conan locating your toolchain to cross build to Android?

I have a ndk-toolchain conan package similar to conan-android-toolchain that sets env_info.CC and env_info.CXX, and my package requires it in its build_requirements.

in ndk-toolchain:

    def package_info(self):
        self.env_info.CC  = os.path.join(self.package_folder, 'toolchain', 'bin', 'clang')
        self.env_info.CXX = os.path.join(self.package_folder, 'toolchain', 'bin', 'clang++')

in package that uses ndk-toolchain for cross compile:

    def build_requirements(self):
        if self.settings.os == 'Android':
            self.build_requires(f'ndk-toolchain/r15c@{self.user}/{self.channel}')

[lasote]

I’ve released a new version removing that check. I think it has become not necessary some time ago but we didn’t remove it. Thanks!