CMake 3.19.6 does not set Boost_LIBRARY_DIR_RELEASE

I’m using CMake 3.19.6 and Boost 1.71 on Ubuntu 20.04. I noticed that in this setup the FindBoost.cmake takes advantage of the CMake configuration files shipped by Boost to configure the Boost usage. Then the _boost_set_legacy_variables_from_config is called, however this macro does not set all the legacy variables like Boost_LIBRARY_DIR_RELEASE, and this breaks my project’s configuration.

I checked the documentation at the beginning of FindBoost.cmake but if I’m correct there’s no mention about the fact that when using the Boost CMake config files the Boost_LIBRARY_DIR_RELEASE will not be set, so I think that the current behavior is not correct.

Can anyone please comment on this? Thanks.