Unknown CMake command `show_variable`

[ta7mid]

The config/addBoost.cmake file uses an unkown CMake command show_variable, so running CMake with -DUNITS_BUILD_WEBSERVER=ON fails as it uses addBoost.cmake.

-- The C compiler identification is AppleClang 17.0.0.17000604
-- The CXX compiler identification is AppleClang 17.0.0.17000604
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /opt/homebrew/Library/Homebrew/shims/mac/super/clang - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/homebrew/Library/Homebrew/shims/mac/super/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- setting up for AppleClang on Darwin-24.6.0
-- adding library llnl-units::units
CMake Error at config/addBoost.cmake:10 (show_variable):
  Unknown CMake command "show_variable".
Call Stack (most recent call first):
  webserver/CMakeLists.txt:19 (include)


-- Configuring incomplete, errors occurred!