[Buildroot] Installing pyyaml with Buildroot

Hi,

I am running into the following error when trying to install pyyaml with
buildroot 2021.05 configuration.

x86_64-buildroot-linux-gnu-gcc.br_real: error: yaml/_yaml.c: No such file
or directory
Error compiling module, falling back to pure Python
pjeyaratnam@proteus:~/branches/sonic3/build/dist$ make yaml-cpp-build
mkdir -p
/home/pjeyaratnam/branches/sonic3/build/dist/per-package/yaml-cpp/host
mkdir -p /home/pjeyaratnam/branches/sonic3/build/dist/per-package

Mysetup is
Python3 enabled
LIBYAML enabled. 0.2.5
pyyaml: 5.4.1

Would it be possible for anyone to point in the right direction on
installing pyyaml on this setup ?

Regards,
Pragash