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I am on MacOS Mojave 10.14. I can compile wxWidget code and have compiled a few demos, etc. The only feature of wxWidget I cannot compile is a wxRichTextCtrl. Whenever I do the following in my main.cpp file I get error:

I used brew install llvm to install LLVM 8 and I want to use the command line tools. I have set the path to the clang executable (in /usr/local/opt/llvm/bin) as suggested by Homebrew and also set LDFLAGS and CPPFLAGS as they suggest. When I compile a simple program I get

First off I am on OSX Mojave 10.14, I have previously upgraded it from 10.13. I bought it new with 10.13.

I am trying to follow this tutorial:

https://scotch.io/tutorials/build-a-restful-json-api-with-rails-5-part-one

I want to make sure that I have the same environment setup using the same version of rails and ruby.

When I try to use rbenv to change my version of ruby (currently 2.6.1) to 2.3.1 I use the following command:

rbenv install 2.3.1

And I get the following error:

file.c:23:10: fatal error: 'CoreFoundation/CFString.h' file not found

I have tried looking on the internet where CFString.h might be, and I have found this useful command to list the directories where clang searches:

echo "#include " | clang -v -x c -

This is the output:

I am trying to write a script that uses a library compiled with clang and another library compiled with G++, I get the following error:

ld.lld: error: undefined symbol: myFunction()

Which (according to this Difference between string and char[] types in C++) is apparently due to std::string meaning different things in different versions of G++ and clang.

Does this mean I have to rewrite the Makefile of my target library to use the same version of G++/Clang? Because that seems like an awful amount of effort just to link a prewritten library, and I think I must be missing something here.

More info

I am compiling v8_shell using ninja -C out/debug

Long story short, I'm building jsoncpp through another library's build system (webrtc's, which to say is behemoth would be an understatement). What that means is that I'm navigating through a build system I have little control over and have little familiarity with.

Suffice to say that when I build libjsoncpp.a on MacOS, the resulting file works perfectly fine. When I compile on Linux, linking with the resulting .a results in undefined reference for everything I use. Diving into the file, I noticed that while the MacOS version appears "normal", like so (excerpt):