[INFO] updating cached repository intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option" "work/ex/beta-1.37-6/sources/1.36.0/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 48e8a4eda3c5524b42a376dcad30a64cb38cdf12
[INFO] sha for GitHub repo intrepion/example-x-rust-x-rustbyexample-com-x-std-option: 48e8a4eda3c5524b42a376dcad30a64cb38cdf12
[INFO] validating manifest of intrepion/example-x-rust-x-rustbyexample-com-x-std-option 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 intrepion/example-x-rust-x-rustbyexample-com-x-std-option 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 intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] finished frobbing intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] frobbed toml for intrepion/example-x-rust-x-rustbyexample-com-x-std-option written to work/ex/beta-1.37-6/sources/1.36.0/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option/Cargo.toml
[INFO] started frobbing intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] finished frobbing intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] frobbed toml for intrepion/example-x-rust-x-rustbyexample-com-x-std-option written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/intrepion/example-x-rust-x-rustbyexample-com-x-std-option/Cargo.toml
[INFO] crate intrepion/example-x-rust-x-rustbyexample-com-x-std-option 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 intrepion/example-x-rust-x-rustbyexample-com-x-std-option 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-6/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/intrepion/example-x-rust-x-rustbyexample-com-x-std-option:/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] 62c34531c1f040367241c51a289959dd5ac67bd3860ff38c9211bed4a397ef0d
[INFO] running `"docker" "start" "-a" "62c34531c1f040367241c51a289959dd5ac67bd3860ff38c9211bed4a397ef0d"`
[INFO] [stderr]    Compiling example-x-rust-x-rustbyexample-com-x-std-option v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `none`
[INFO] [stderr]   --> src/main.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |     let none: Option<i32> = None;
[INFO] [stderr]    |         ^^^^ help: consider prefixing with an underscore: `_none`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.23s
[INFO] running `"docker" "inspect" "62c34531c1f040367241c51a289959dd5ac67bd3860ff38c9211bed4a397ef0d"`
[INFO] running `"docker" "rm" "-f" "62c34531c1f040367241c51a289959dd5ac67bd3860ff38c9211bed4a397ef0d"`
[INFO] [stdout] 62c34531c1f040367241c51a289959dd5ac67bd3860ff38c9211bed4a397ef0d
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/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/intrepion/example-x-rust-x-rustbyexample-com-x-std-option:/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" "test" "--frozen" "--no-run"`
[INFO] [stdout] e7fc0674c0701e7c8e69b4184450ad7d8d64cc17ba921b6bd6693dd684d85c30
[INFO] running `"docker" "start" "-a" "e7fc0674c0701e7c8e69b4184450ad7d8d64cc17ba921b6bd6693dd684d85c30"`
[INFO] [stderr]    Compiling example-x-rust-x-rustbyexample-com-x-std-option v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `none`
[INFO] [stderr]   --> src/main.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |     let none: Option<i32> = None;
[INFO] [stderr]    |         ^^^^ help: consider prefixing with an underscore: `_none`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.29s
[INFO] running `"docker" "inspect" "e7fc0674c0701e7c8e69b4184450ad7d8d64cc17ba921b6bd6693dd684d85c30"`
[INFO] running `"docker" "rm" "-f" "e7fc0674c0701e7c8e69b4184450ad7d8d64cc17ba921b6bd6693dd684d85c30"`
[INFO] [stdout] e7fc0674c0701e7c8e69b4184450ad7d8d64cc17ba921b6bd6693dd684d85c30
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-6/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/intrepion/example-x-rust-x-rustbyexample-com-x-std-option:/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" "test" "--frozen"`
[INFO] [stdout] 7af2b70e2da5ddee158925f9b2c59b5cbf08cdb04c25a363c0113bc0ae962490
[INFO] running `"docker" "start" "-a" "7af2b70e2da5ddee158925f9b2c59b5cbf08cdb04c25a363c0113bc0ae962490"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.00s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/example_x_rust_x_rustbyexample_com_x_std_option-a79a1db6a34ba3aa
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "7af2b70e2da5ddee158925f9b2c59b5cbf08cdb04c25a363c0113bc0ae962490"`
[INFO] running `"docker" "rm" "-f" "7af2b70e2da5ddee158925f9b2c59b5cbf08cdb04c25a363c0113bc0ae962490"`
[INFO] [stdout] 7af2b70e2da5ddee158925f9b2c59b5cbf08cdb04c25a363c0113bc0ae962490