The file changes would apply only in a punctual configuration of environment and do not support the whole statement in the description.

LLVM is unable to emit code for an older LLVM.

When cross compiling both llvm should match or at least the target must be newer.

I don't know about OpenBSD, but binding llvm-3.8 with openbsd can't be right. You can build sources and use other llvm version.

Feel free to ask for support for some issue you might be experiencing. Meanwhile I will close this.

Please specify the LLVM_CONFIG environment variable on the host target to specify which LLVM to use. For example:

LLVM_CONFIG=/opt/llvm3.8/bin/llvm-config \
  bin/crystal build src/compiler/crystal.cr \
  -o crystal -Dwithout_zlib -Dwithout_openssl

I use this a lot to test against different LLVM versions locally.

Hrmm, ok.

This did resolve my cross-compiling issues which were due to linking problems since LLVMCreateTargetDataLayout isn't defined in v 3.8

I'll try specifying LLVM_CONFIG as @ysbaddaden suggests

I don't actually need v3.8 installed for this to work, I just need the compatible methods specified so I can cross-compile an object file that can be used on the OpenBSD side.

I'm building via these instructions: https://gist.github.com/wmoxam/d06f9ccc82e03f6fea64747d82caa421