[INFO] updating cached repository KuroAku/complex
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/KuroAku/complex
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/KuroAku/complex" "work/ex/beta-1.37-6/sources/1.36.0/gh/KuroAku/complex"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/KuroAku/complex'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/KuroAku/complex" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/KuroAku/complex"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/KuroAku/complex'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8b9c3f4d9886305e84e7fe532f2ddc9c217e9d9e
[INFO] sha for GitHub repo KuroAku/complex: 8b9c3f4d9886305e84e7fe532f2ddc9c217e9d9e
[INFO] validating manifest of KuroAku/complex on toolchain 1.36.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of KuroAku/complex on toolchain beta-2019-07-23
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing KuroAku/complex
[INFO] finished frobbing KuroAku/complex
[INFO] frobbed toml for KuroAku/complex written to work/ex/beta-1.37-6/sources/1.36.0/gh/KuroAku/complex/Cargo.toml
[INFO] started frobbing KuroAku/complex
[INFO] finished frobbing KuroAku/complex
[INFO] frobbed toml for KuroAku/complex written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/KuroAku/complex/Cargo.toml
[INFO] crate KuroAku/complex already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.36.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing KuroAku/complex against beta-2019-07-23 for beta-1.37-6
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-4/beta-2019-07-23:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/KuroAku/complex:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-07-23" "build" "--frozen"`
[INFO] [stdout] 903e74f159e0872f55826df6ed1836c5e9c0d8949166fa1da74058932c2a3af6
[INFO] running `"docker" "start" "-a" "903e74f159e0872f55826df6ed1836c5e9c0d8949166fa1da74058932c2a3af6"`
[INFO] [stderr]    Compiling regex v0.2.2
[INFO] [stderr]    Compiling complex v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(use_extern_macros)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `complex`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "903e74f159e0872f55826df6ed1836c5e9c0d8949166fa1da74058932c2a3af6"`
[INFO] running `"docker" "rm" "-f" "903e74f159e0872f55826df6ed1836c5e9c0d8949166fa1da74058932c2a3af6"`
[INFO] [stdout] 903e74f159e0872f55826df6ed1836c5e9c0d8949166fa1da74058932c2a3af6