Build fails on linux if libunwind is installed

[Aatch]

I have libunwind installed as a pre-req for another package, this causes rust_unwind.h to fail the build because of the re-typedefing of _Unwind_Exception.

Unfortunately, I can't seem to find a decent way of detecting that unwind.h has been included, other than using it's header guard macro.

This is building with --enable-clang on. Also, I am using the latest trunk.

[thestinger]

Do you know where it gets included from? I have libunwind installed as a dependency of perf, but I haven't run into this.

[Aatch]

The header being included is /usr/include/unwind.h. The line that is throwing the warning is inside an #ifndef __FreeBSD__ directive.

I'm running archlinux, which installs the headers for everything, I know that other distros often have a separate -dev or -devel package that has the headers.

[thestinger]

I'm also on Arch by the way (x86_64) and testing against the latest incoming/master doesn't hit this.

[Aatch]

I'm running clang 3.3 if that helps.

I also seem to be running an SVN build from AUR, I'm updating to the latest build, then I'll switch to the official package and see if that works.

[Aatch]

Tried it with the clang from the official repo, still happens...

[thestinger]

Ah, I'm silly and missed that you were compiling with clang, I interpreted it as you building clang along with Rust's LLVM. Same issue comes up here.

[Aatch]

Fixed by #5646