[boost] boost_check_library.py: correct handling of header-only libs?

This script fails for me: https://github.com/boostorg/boost/blob/master/status/boost_check_library.py#... Because there is no libs/beast/build. But Beast is header-only and has no src/ directory, is this correct? Apologies for posting to the list, but there is no Issues tab on the boostorg/boost repo. Thanks