`In file included from /home/john/hpx_is_sentinel_for/libs/iterator_support/tests/unit/is_sentinel_for.cpp:8:0:
/home/john/hpx_is_sentinel_for/libs/testing/include_compatibility/hpx/testing.hpp:18:2: warning: #warning "The header hpx/testing.hpp is deprecated,     please include hpx/modules/testing.hpp instead" [-Wcpp]
 #warning "The header hpx/testing.hpp is deprecated, \
  ^~~~~~~
`