find_package(UseComponents COMPONENTS Comp1 Comp2)

if (NOT UseComponents_FOUND)
  message (FATAL_ERROR "package UseComponents Not Found.")
endif()
if (NOT UseComponents_Comp1_FOUND)
  message (FATAL_ERROR "package UseComponents, component Comp1 Not Found.")
endif()
if (NOT UseComponents_Comp2_FOUND)
  message (FATAL_ERROR "package UseComponents, component Comp2 Not Found.")
endif()