On Tue, Jan 02, 2024 at 12:17:26PM +0000, Stuart Henderson wrote: > I think these should append rather than override CXXFLAGS?
Yes. Also, MODCMAKE_configure already passes CXXFLAGS, so this should do: CXXFLAGS += -D_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION
