Hi, I am currently trying to compile cln with linkage against libc++. My aproach was: /configure CXX=/usr/bin/clang++ CXXFLAGS=-stdlib=libc++ However this does not work as I get erroneus output such as In file included from base/cl_alloca.cc:4: In file included from ./base/cl_sysdep.h:56: In file included from ./base/cl_macros.h:7: ../include/cln/exception.h:14:24: error: implicit instantiation of undefined template 'std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >' : std::runtime_error(std::string()) {} ^ /usr/bin/../lib/c++/v1/iosfwd:187:28: note: template is declared here class _LIBCPP_TYPE_VIS basic_string; What does this mean and what am I doing wrong? I need this in order to compile ginac with the same linkage as it is used in a project with c++11 features. Best regards, Stefan