Cross compiling to ARM

There is the option of using compilers from the PlatformIO (https://platformio.org) project, they install locally in .platofrmio/lib and you can target most platforms including arm variants. However this by default isn’t going to provide full platform support for compiling for Apple or Raspberry PI, but could most likely be extended for those use cases. There is also a clib that supports ARM that you can use to compile static files with: https://musl.libc.org