I tried `./configure --llvm-root=/usr && make` but it fails to build `libstd`. The error message is: ``` /home/omasanori/work/rust/src/libstd/lib.rs:74:1: 74:19 error: multiple dylib candidates for `libc` found /home/omasanori/work/rust/src/libstd/lib.rs:74 extern crate libc; ^~~~~~~~~~~~~~~~~~ /home/omasanori/work/rust/src/libstd/lib.rs:74:1: 74:19 note: candidate #1: /usr/lib64/liblibc-3574b280-0.11-pre.so /home/omasanori/work/rust/src/libstd/lib.rs:74 extern crate libc; ^~~~~~~~~~~~~~~~~~ /home/omasanori/work/rust/src/libstd/lib.rs:74:1: 74:19 note: candidate #2: /home/omasanori/work/rust/x86_64-unknown-linux-gnu/stage0/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-3574b280-0.11-pre.so /home/omasanori/work/rust/src/libstd/lib.rs:74 extern crate libc; ^~~~~~~~~~~~~~~~~~ error: aborting due to previous error ```