[INFO] crate panic-never 0.1.0 is already in cache
[INFO] extracting crate panic-never 0.1.0 into work/ex/beta-1.38-1/sources/1.37.0/reg/panic-never/0.1.0
[INFO] extracting crate panic-never 0.1.0 into work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/panic-never/0.1.0
[INFO] validating manifest of panic-never-0.1.0 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 panic-never-0.1.0 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 panic-never-0.1.0
[INFO] finished frobbing panic-never-0.1.0
[INFO] frobbed toml for panic-never-0.1.0 written to work/ex/beta-1.38-1/sources/1.37.0/reg/panic-never/0.1.0/Cargo.toml
[INFO] started frobbing panic-never-0.1.0
[INFO] finished frobbing panic-never-0.1.0
[INFO] frobbed toml for panic-never-0.1.0 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/panic-never/0.1.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 panic-never-0.1.0 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/panic-never/0.1.0:/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-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 9a0ddba9392099037d7da649a664ad00a9b4042cedcca47363d622704a106491
[INFO] running `"docker" "start" "-a" "9a0ddba9392099037d7da649a664ad00a9b4042cedcca47363d622704a106491"`
[INFO] [stderr]    Compiling panic-never v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.13s
[INFO] running `"docker" "inspect" "9a0ddba9392099037d7da649a664ad00a9b4042cedcca47363d622704a106491"`
[INFO] running `"docker" "rm" "-f" "9a0ddba9392099037d7da649a664ad00a9b4042cedcca47363d622704a106491"`
[INFO] [stdout] 9a0ddba9392099037d7da649a664ad00a9b4042cedcca47363d622704a106491
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-7/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/reg/panic-never/0.1.0:/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-2019-08-13" "test" "--frozen" "--no-run"`
[INFO] [stdout] 6cac1322b6e547de2edf433f00ffe731b4d4b0bca4285f38f714900ff4672541
[INFO] running `"docker" "start" "-a" "6cac1322b6e547de2edf433f00ffe731b4d4b0bca4285f38f714900ff4672541"`
[INFO] [stderr]    Compiling panic-never v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] error[E0152]: duplicate lang item found: `panic_impl`.
[INFO] [stderr]   --> src/lib.rs:48:1
[INFO] [stderr]    |
[INFO] [stderr] 48 | / fn panic(_: &PanicInfo<'_>) -> ! {
[INFO] [stderr] 49 | |     extern "Rust" {
[INFO] [stderr] 50 | |         #[link_name = "\nerror(panic-never): your program contains at least one panicking branch"]
[INFO] [stderr] 51 | |         fn undefined() -> !;
[INFO] [stderr] ...  |
[INFO] [stderr] 54 | |     unsafe { undefined() }
[INFO] [stderr] 55 | | }
[INFO] [stderr]    | |_^
[INFO] [stderr]    |
[INFO] [stderr]    = note: first defined in crate `std`.
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0152`.
[INFO] [stderr] error: Could not compile `panic-never`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "6cac1322b6e547de2edf433f00ffe731b4d4b0bca4285f38f714900ff4672541"`
[INFO] running `"docker" "rm" "-f" "6cac1322b6e547de2edf433f00ffe731b4d4b0bca4285f38f714900ff4672541"`
[INFO] [stdout] 6cac1322b6e547de2edf433f00ffe731b4d4b0bca4285f38f714900ff4672541