[INFO] cloning repository suelz/chapter_4
[INFO] running `"git" "clone" "--bare" "git://github.com/suelz/chapter_4.git" "work/cache/sources/gh/suelz/chapter_4"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/suelz/chapter_4'...
[INFO] running `"git" "clone" "work/cache/sources/gh/suelz/chapter_4" "work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4"`
[INFO] [stderr] Cloning into 'work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/suelz/chapter_4" "work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/suelz/chapter_4"`
[INFO] [stderr] Cloning into 'work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/suelz/chapter_4'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 5266a4ada4918881254cc79de937fbc229bb69a4
[INFO] sha for GitHub repo suelz/chapter_4: 5266a4ada4918881254cc79de937fbc229bb69a4
[INFO] validating manifest of suelz/chapter_4 on toolchain master#c8865d8e195813ade6b84434ac9f8850e7112d1a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of suelz/chapter_4 on toolchain try#e212b7d492c96d3837691ba29d32d5f468933fb8
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing suelz/chapter_4
[INFO] finished frobbing suelz/chapter_4
[INFO] frobbed toml for suelz/chapter_4 written to work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4/Cargo.toml
[INFO] started frobbing suelz/chapter_4
[INFO] finished frobbing suelz/chapter_4
[INFO] frobbed toml for suelz/chapter_4 written to work/ex/pr-61629/sources/try#e212b7d492c96d3837691ba29d32d5f468933fb8/gh/suelz/chapter_4/Cargo.toml
[INFO] crate suelz/chapter_4 already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e212b7d492c96d3837691ba29d32d5f468933fb8-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing suelz/chapter_4 against master#c8865d8e195813ade6b84434ac9f8850e7112d1a for pr-61629
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-61629/worker-2/master#c8865d8e195813ade6b84434ac9f8850e7112d1a:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4:/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=forbid" "-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" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "build" "--frozen"`
[INFO] [stdout] cf706eb264f1d47c5b16eef021e85a1d913363bf41df35b84128fe573cc87d28
[INFO] running `"docker" "start" "-a" "cf706eb264f1d47c5b16eef021e85a1d913363bf41df35b84128fe573cc87d28"`
[INFO] [stderr]    Compiling ch4 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `word`
[INFO] [stderr]   --> src/main.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |     let word = first_word(&x);
[INFO] [stderr]    |         ^^^^ help: consider prefixing with an underscore: `_word`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:26:9
[INFO] [stderr]    |
[INFO] [stderr] 26 |     let mut x = String::from("Conor Kennedy");
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.45s
[INFO] running `"docker" "inspect" "cf706eb264f1d47c5b16eef021e85a1d913363bf41df35b84128fe573cc87d28"`
[INFO] running `"docker" "rm" "-f" "cf706eb264f1d47c5b16eef021e85a1d913363bf41df35b84128fe573cc87d28"`
[INFO] [stdout] cf706eb264f1d47c5b16eef021e85a1d913363bf41df35b84128fe573cc87d28
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-61629/worker-2/master#c8865d8e195813ade6b84434ac9f8850e7112d1a:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4:/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=forbid" "-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" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "test" "--frozen" "--no-run"`
[INFO] [stdout] d25334ca396982d30f19f41067806e3fe115640e086a02e2645a05db11c9d398
[INFO] running `"docker" "start" "-a" "d25334ca396982d30f19f41067806e3fe115640e086a02e2645a05db11c9d398"`
[INFO] [stderr]    Compiling ch4 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `word`
[INFO] [stderr]   --> src/main.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |     let word = first_word(&x);
[INFO] [stderr]    |         ^^^^ help: consider prefixing with an underscore: `_word`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:26:9
[INFO] [stderr]    |
[INFO] [stderr] 26 |     let mut x = String::from("Conor Kennedy");
[INFO] [stderr]    |         ----^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.41s
[INFO] running `"docker" "inspect" "d25334ca396982d30f19f41067806e3fe115640e086a02e2645a05db11c9d398"`
[INFO] running `"docker" "rm" "-f" "d25334ca396982d30f19f41067806e3fe115640e086a02e2645a05db11c9d398"`
[INFO] [stdout] d25334ca396982d30f19f41067806e3fe115640e086a02e2645a05db11c9d398
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-61629/worker-2/master#c8865d8e195813ade6b84434ac9f8850e7112d1a:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-61629/sources/master#c8865d8e195813ade6b84434ac9f8850e7112d1a/gh/suelz/chapter_4:/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=forbid" "-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" "+c8865d8e195813ade6b84434ac9f8850e7112d1a-alt" "test" "--frozen"`
[INFO] [stdout] 39ed2c7a80331e60044a65afbba4b08c29613fd5067b6ff3fd45d2b7dfaed65a
[INFO] running `"docker" "start" "-a" "39ed2c7a80331e60044a65afbba4b08c29613fd5067b6ff3fd45d2b7dfaed65a"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.01s
[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] [stderr]      Running /opt/crater/target/debug/deps/ch4-6499f699bd75a741
[INFO] running `"docker" "inspect" "39ed2c7a80331e60044a65afbba4b08c29613fd5067b6ff3fd45d2b7dfaed65a"`
[INFO] running `"docker" "rm" "-f" "39ed2c7a80331e60044a65afbba4b08c29613fd5067b6ff3fd45d2b7dfaed65a"`
[INFO] [stdout] 39ed2c7a80331e60044a65afbba4b08c29613fd5067b6ff3fd45d2b7dfaed65a