cmake KWSYS_CXX_HAS_UNSETENV examples

Kitware/VTK Utilities/KWSys/vtksys/CMakeLists.txt :447

set_property(SOURCE SystemTools.cxx APPEND PROPERTY COMPILE_DEFINITIONS
    KWSYS_CXX_HAS_SETENV=${KWSYS_CXX_HAS_SETENV}
    KWSYS_CXX_HAS_UNSETENV=${KWSYS_CXX_HAS_UNSETENV}
    KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H=${KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H}
    KWSYS_CXX_HAS_UTIMES=${KWSYS_CXX_HAS_UTIMES}
    KWSYS_CXX_HAS_UTIMENSAT=${KWSYS_CXX_HAS_UTIMENSAT}
    KWSYS_CXX_STAT_HAS_ST_MTIM=${KWSYS_CXX_STAT_HAS_ST_MTIM}
    KWSYS_CXX_STAT_HAS_ST_MTIMESPEC=${KWSYS_CXX_STAT_HAS_ST_MTIMESPEC}
    )

InsightSoftwareConsortium/ITK Modules/ThirdParty/KWSys/src/KWSys/CMakeLists.txt :419

set_property(SOURCE SystemTools.cxx APPEND PROPERTY COMPILE_DEFINITIONS
    KWSYS_CXX_HAS_SETENV=${KWSYS_CXX_HAS_SETENV}
    KWSYS_CXX_HAS_UNSETENV=${KWSYS_CXX_HAS_UNSETENV}
    KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H=${KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H}
    KWSYS_CXX_HAS_UTIMES=${KWSYS_CXX_HAS_UTIMES}
    KWSYS_CXX_HAS_UTIMENSAT=${KWSYS_CXX_HAS_UTIMENSAT}
    KWSYS_CXX_STAT_HAS_ST_MTIM=${KWSYS_CXX_STAT_HAS_ST_MTIM}
    KWSYS_CXX_STAT_HAS_ST_MTIMESPEC=${KWSYS_CXX_STAT_HAS_ST_MTIMESPEC}
    )

Kitware/kwiver vital/kwiversys/CMakeLists.txt :513

SET_PROPERTY(SOURCE SystemTools.cxx APPEND PROPERTY COMPILE_DEFINITIONS
    KWSYS_CXX_HAS_SETENV=${KWSYS_CXX_HAS_SETENV}
    KWSYS_CXX_HAS_UNSETENV=${KWSYS_CXX_HAS_UNSETENV}
    KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H=${KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H}
    KWSYS_CXX_HAS_UTIMES=${KWSYS_CXX_HAS_UTIMES}
    KWSYS_CXX_HAS_UTIMENSAT=${KWSYS_CXX_HAS_UTIMENSAT}
    KWSYS_CXX_STAT_HAS_ST_MTIM=${KWSYS_CXX_STAT_HAS_ST_MTIM}
    KWSYS_CXX_STAT_HAS_ST_MTIMESPEC=${KWSYS_CXX_STAT_HAS_ST_MTIMESPEC}
    )

ornladios/ADIOS2 thirdparty/KWSys/adios2sys/CMakeLists.txt :427

set_property(SOURCE SystemTools.cxx APPEND PROPERTY COMPILE_DEFINITIONS
    KWSYS_CXX_HAS_SETENV=${KWSYS_CXX_HAS_SETENV}
    KWSYS_CXX_HAS_UNSETENV=${KWSYS_CXX_HAS_UNSETENV}
    KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H=${KWSYS_CXX_HAS_ENVIRON_IN_STDLIB_H}
    KWSYS_CXX_HAS_UTIMES=${KWSYS_CXX_HAS_UTIMES}
    KWSYS_CXX_HAS_UTIMENSAT=${KWSYS_CXX_HAS_UTIMENSAT}
    KWSYS_CXX_STAT_HAS_ST_MTIM=${KWSYS_CXX_STAT_HAS_ST_MTIM}
    KWSYS_CXX_STAT_HAS_ST_MTIMESPEC=${KWSYS_CXX_STAT_HAS_ST_MTIMESPEC}
    )