Can you try invoking the compiler like this instead?
nim --cc:clang
--clang.exe:/home/hdias/tmp/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang
--clang.linkerexe:/home/hdias/tmp/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang
--os:android --cpu:arm64
-t:-I/home/hdias/tmp/android-ndk-r19c/toolchains/llvm/prebuilt/linux-x86_64/sysroot
test.nim
RunThis should let Nim know which cross compiler should be used.
