[seL4] How to build compile seL4 along with another C++ project that includes <stdlib.h>

I want to run my C++ project in a camkes image for i.mx6. This image should be statically linked.

I have a camkes app in https://github.com/seL4/camkes-manifest. The app's CMakeLists.txt includes my project with add_subdirectory("${CMAKE_CURRENT_LIST_DIR}/workspace_DDSHelloWorld"), which is a simple DDS example https://fast-dds.docs.eprosima.com/en/latest/fastdds/getting_started/simple_... that also uses CMake as its build system. The entire app is built with ../init-build.sh -DPLATFORM=sabre -DCAMKES_APP=dds.

However, the build fails. 1. My project includes <stdint.h>, but sel4 uses the -nostdinc and -nostdinc++ flags, so I get the error "stdint.h: No such file or directory". How do I make my C++ project include seL4's musllibc instead? 2. My project includes other C++ headers like <functional>. Is there any way to build seL4 with C++ headers?