Example to crossbuild Conan Center recipes with system dependencies on Ubuntu

Note: assuming Docker is running on x86_64

git clone https://github.com/jcar87/cci-crossbuild-example.git
cd cci-crossbuild-example
docker build . -t cci-crossbuild-example

Example only

Drop into a shell inside the image:

docker run --rm -ti cci-crossbuild-example /bin/bash

Issue a conan install command for opencv/4.10.0 - allow Conan to build missing dependencies.

conan install --require=opencv/4.10.0 --envs-generation=false --build=missing --profile arm64 --conf:all tools.system.package_manager:mode=install

Ubuntu is multiarch (read more) - this way we are able to resolve "system" dependencies while keeping the sysroot at /

This is achieved by:

• Enabling the arm64 architecture in dpkg with dpkg --add-architecture
• Amending the apt sources such that they point to the correct archives for each architecture
• Using the crossbuild toolchain provided by the crossbuild-essential-arm64
• Using pkg-config tailored for the crossbuild environment, by installing the pkgconf:arm64 package.
  • This can be confirmed with aarch64-linux-gnu-pkgconf --dump-personality
• Reflecting the above in a Conan profile:
  • arch=armv8
  • Compiler executables are:
    • aarch64-linux-gnu-gcc for the C compiler
    • aarch64-linux-gnu-g++ for the C++ compiler
  • The tools.gnu:pkg_config conf
    • Point to /usr/bin/aarch64-linux-gnu-pkgconf, this allows it to find the system dependencies for the "host" architecture