"fixup value out of range" error (LLVM bug?)

[jeehoonkang]

코드를 좀만 건드려도 다음과 같은 에러가 납니다

$ make qemu 
cargo xbuild --manifest-path kernel-rs/Cargo.toml --target kernel-rs/riscv64gc-unknown-none-elfhf.json --release
   Compiling core v0.0.0 (/kaist-cp-home/jeehoon.kang/.rustup/toolchains/nightly-2020-06-12-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/libcore)
   Compiling compiler_builtins v0.1.32
   Compiling rustc-std-workspace-core v1.99.0 (/kaist-cp-home/jeehoon.kang/.rustup/toolchains/nightly-2020-06-12-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src/tools/rustc-std-workspace-core)
   Compiling alloc v0.0.0 (/tmp/cargo-xbuild.McU5pMRsTKs6)
    Finished release [optimized + debuginfo] target(s) in 9.65s
   Compiling autocfg v1.0.0
   Compiling bitflags v1.2.1
   Compiling scopeguard v1.1.0
   Compiling num-traits v0.2.12
   Compiling num-integer v0.1.43
   Compiling num-iter v0.1.41
   Compiling rv6-kernel v0.1.0 (/kaist-cp-home/jeehoon.kang/Works/rv6/kernel-rs)
error: fixup value out of range

error: aborting due to previous error

error: could not compile `rv6-kernel`.

To learn more, run the command again with --verbose.
make: *** [Makefile:98: kernel-rs/target/riscv64gc-unknown-none-elfhf/release/librv6_kernel.a] Error 101

검색해보니 LLVM 버그를 밟은 것 같네요 Aㅏ... rust-lang/rust#74813
rust-lang/rust에서 해결해줄때까지 기다리겠습니다.

일단 rust code를 debug로 컴파일하고, 대신 debug profile에 opt-level=1을 주는걸로 바꾸겠습니다.