Using Clang 9 on Windows b2 toolset-clang-linux cxxstd=2a . I am seeing lots of these warnings In file included from ..\..\..\boost/test/included/unit_test.hpp:23: In file included from ..\..\..\boost/test/impl/execution_monitor.ipp:37: In file included from ..\..\..\boost/exception/diagnostic_information.hpp:11: ..\..\..\boost/exception/info.hpp:134:21: warning: delete called on non-final 'boost::exception_detail::error_info_container_impl' that has virtual functions but non-virtual destructor [-Wdelete-non-abstract-non-virtual-dtor] delete this; ^ It seems that trying to supress is ineffective with -Wno-delete-non-abstract-non-virtual-dtor Perhaps by design? https://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html#w... te-non-abstract-non-virtual-dtor -Wdelete-non-abstract-non-virtual-dtor https://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html Diagnostic text: warning: delete destructor called on non-final B that has virtual functions but non-virtual destructor -Wdelete-non-virtual-dtor https://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html Some of the diagnostics controlled by this flag are enabled by default. Controls -Wdelete-abstract-non-virtual-dtor https://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html , -Wdelete-non-abstract-non-virtual-dtor https://releases.llvm.org/9.0.0/tools/clang/docs/DiagnosticsReference.html . Should I be concerned about this? Paul Paul A. Bristow Prizet Farmhouse Kendal, Cumbria LA8 8AB UK