[INFO] updating cached repository masterfix/radon
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/masterfix/radon
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/masterfix/radon" "work/ex/beta-1.38-1/sources/1.37.0/gh/masterfix/radon"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/masterfix/radon'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/masterfix/radon" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/masterfix/radon"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/masterfix/radon'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9d9173dc8d3462d388e7b48bbd3f7f5952ccea70
[INFO] sha for GitHub repo masterfix/radon: 9d9173dc8d3462d388e7b48bbd3f7f5952ccea70
[INFO] validating manifest of masterfix/radon on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of masterfix/radon on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing masterfix/radon
[INFO] finished frobbing masterfix/radon
[INFO] frobbed toml for masterfix/radon written to work/ex/beta-1.38-1/sources/1.37.0/gh/masterfix/radon/Cargo.toml
[INFO] started frobbing masterfix/radon
[INFO] finished frobbing masterfix/radon
[INFO] frobbed toml for masterfix/radon written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/masterfix/radon/Cargo.toml
[INFO] crate masterfix/radon already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing masterfix/radon against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/masterfix/radon:/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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] d4b7d23b093ab4c65b324d05c6e92e137d3b17657a214682d7ade8a087b22e61
[INFO] running `"docker" "start" "-a" "d4b7d23b093ab4c65b324d05c6e92e137d3b17657a214682d7ade8a087b22e61"`
[INFO] [stderr]    Compiling radon v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(lang_items)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0522]: definition of an unknown language item: `panic_fmt`
[INFO] [stderr]  --> src/main.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | #[lang = "panic_fmt"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^ definition of unknown language item `panic_fmt`
[INFO] [stderr] 
[INFO] [stderr] error: `#[panic_handler]` function required, but not found
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0522, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0522`.
[INFO] [stderr] error: Could not compile `radon`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d4b7d23b093ab4c65b324d05c6e92e137d3b17657a214682d7ade8a087b22e61"`
[INFO] running `"docker" "rm" "-f" "d4b7d23b093ab4c65b324d05c6e92e137d3b17657a214682d7ade8a087b22e61"`
[INFO] [stdout] d4b7d23b093ab4c65b324d05c6e92e137d3b17657a214682d7ade8a087b22e61