Missing symbol `typeinfo for llvm::raw_ostream' in LLVM-4.0.so

How can I understand why this symbol is missing: https://bugs.llvm.org/show_bug.cgi?id=33683



It seems you are building some code using the LLVM headers and linking to the LLVM library and getting this error, is this correct?

The LLVM library you’re linking to was built with -fno-rtti. You need to use the same flag for every translation unit that is using a header from LLVM. Alternatively you can rebuild LLVM and disable this flag.

LLVM usually comes with llvm-config, which is a tool that can give you the list of compilation flags that you should use to build your code to match how LLVM was built.