[INFO] updating cached repository BenjaminGuenin/rust-programming-tutorial
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/BenjaminGuenin/rust-programming-tutorial
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/BenjaminGuenin/rust-programming-tutorial" "work/ex/beta-1.38-1/sources/1.37.0/gh/BenjaminGuenin/rust-programming-tutorial"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/BenjaminGuenin/rust-programming-tutorial'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/BenjaminGuenin/rust-programming-tutorial" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 1c2bd68e28b9b496e1604e619e56fab798015000
[INFO] sha for GitHub repo BenjaminGuenin/rust-programming-tutorial: 1c2bd68e28b9b496e1604e619e56fab798015000
[INFO] validating manifest of BenjaminGuenin/rust-programming-tutorial 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 BenjaminGuenin/rust-programming-tutorial 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 BenjaminGuenin/rust-programming-tutorial
[INFO] finished frobbing BenjaminGuenin/rust-programming-tutorial
[INFO] frobbed toml for BenjaminGuenin/rust-programming-tutorial written to work/ex/beta-1.38-1/sources/1.37.0/gh/BenjaminGuenin/rust-programming-tutorial/Cargo.toml
[INFO] started frobbing BenjaminGuenin/rust-programming-tutorial
[INFO] finished frobbing BenjaminGuenin/rust-programming-tutorial
[INFO] frobbed toml for BenjaminGuenin/rust-programming-tutorial written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial/Cargo.toml
[INFO] crate BenjaminGuenin/rust-programming-tutorial 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 BenjaminGuenin/rust-programming-tutorial 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-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial:/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] 882a29277286bf591a0fed087608f1b7afe9747a481464f1c1c138759ade6868
[INFO] running `"docker" "start" "-a" "882a29277286bf591a0fed087608f1b7afe9747a481464f1c1c138759ade6868"`
[INFO] [stderr]    Compiling rust-programming-tutorial v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `immutable_string`
[INFO] [stderr]  --> src/main.rs:3:9
[INFO] [stderr]   |
[INFO] [stderr] 3 |     let immutable_string = "hello"; // cannot be modified - stored on the stack
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_immutable_string`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/main.rs:11:13
[INFO] [stderr]    |
[INFO] [stderr] 11 |         let s = String::from("hello"); // s is valid from this point forward
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.83s
[INFO] running `"docker" "inspect" "882a29277286bf591a0fed087608f1b7afe9747a481464f1c1c138759ade6868"`
[INFO] running `"docker" "rm" "-f" "882a29277286bf591a0fed087608f1b7afe9747a481464f1c1c138759ade6868"`
[INFO] [stdout] 882a29277286bf591a0fed087608f1b7afe9747a481464f1c1c138759ade6868
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial:/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] 33fd043bbb1f7621f7ff00b70bffc6e090d4f6c27fca280a817b3c75fb7ffad3
[INFO] running `"docker" "start" "-a" "33fd043bbb1f7621f7ff00b70bffc6e090d4f6c27fca280a817b3c75fb7ffad3"`
[INFO] [stderr]    Compiling rust-programming-tutorial v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `immutable_string`
[INFO] [stderr]  --> src/main.rs:3:9
[INFO] [stderr]   |
[INFO] [stderr] 3 |     let immutable_string = "hello"; // cannot be modified - stored on the stack
[INFO] [stderr]   |         ^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_immutable_string`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `s`
[INFO] [stderr]   --> src/main.rs:11:13
[INFO] [stderr]    |
[INFO] [stderr] 11 |         let s = String::from("hello"); // s is valid from this point forward
[INFO] [stderr]    |             ^ help: consider prefixing with an underscore: `_s`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.60s
[INFO] running `"docker" "inspect" "33fd043bbb1f7621f7ff00b70bffc6e090d4f6c27fca280a817b3c75fb7ffad3"`
[INFO] running `"docker" "rm" "-f" "33fd043bbb1f7621f7ff00b70bffc6e090d4f6c27fca280a817b3c75fb7ffad3"`
[INFO] [stdout] 33fd043bbb1f7621f7ff00b70bffc6e090d4f6c27fca280a817b3c75fb7ffad3
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-3/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/BenjaminGuenin/rust-programming-tutorial:/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"`
[INFO] [stdout] cac50d1aa495503e724608c4878aead099ff620ae50ab20f6d08a66a3a467ca3
[INFO] running `"docker" "start" "-a" "cac50d1aa495503e724608c4878aead099ff620ae50ab20f6d08a66a3a467ca3"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/rust_programming_tutorial-be25e6828ef08b7b
[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" "cac50d1aa495503e724608c4878aead099ff620ae50ab20f6d08a66a3a467ca3"`
[INFO] running `"docker" "rm" "-f" "cac50d1aa495503e724608c4878aead099ff620ae50ab20f6d08a66a3a467ca3"`
[INFO] [stdout] cac50d1aa495503e724608c4878aead099ff620ae50ab20f6d08a66a3a467ca3