Tests/RunCMake/find_package/FromPrefixPath.cmake

set(ENV_PATH "$ENV{PATH}")
set(ENV{PATH} "")
foreach(path "/does_not_exist" "/PackageRoot" "")
  unset(Resolved_FOUND CACHE)
  set(Resolved_DIR "")
  set(CMAKE_PREFIX_PATH "${CMAKE_CURRENT_SOURCE_DIR}${path}")
  find_package(Resolved QUIET)
  message(STATUS "Resolved_FOUND='${Resolved_FOUND}'")
endforeach()

set(CMAKE_FIND_USE_CMAKE_PATH OFF)
set(CMAKE_PREFIX_PATH )
foreach(path "/does_not_exist" "/PackageRoot" "")
  unset(Resolved_FOUND CACHE)
  set(Resolved_DIR "")
  set(CMAKE_PREFIX_PATH "${CMAKE_CURRENT_SOURCE_DIR}${path}")
  find_package(Resolved QUIET)
  message(STATUS "Resolved_FOUND='${Resolved_FOUND}'")
endforeach()

set(CMAKE_FIND_USE_CMAKE_PATH ON)
foreach(path "/does_not_exist" "/PackageRoot" "")
  unset(Resolved_FOUND CACHE)
  set(Resolved_DIR "")
  set(CMAKE_PREFIX_PATH "${CMAKE_CURRENT_SOURCE_DIR}${path}")
  find_package(Resolved NO_CMAKE_PATH QUIET)
  message(STATUS "Resolved_FOUND='${Resolved_FOUND}'")
endforeach()
set(ENV{PATH} "${ENV_PATH}")