[INFO] updating cached repository jheloper/rust-playground
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/jheloper/rust-playground
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/jheloper/rust-playground" "work/ex/beta-1.38-1/sources/1.37.0/gh/jheloper/rust-playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/jheloper/rust-playground'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/jheloper/rust-playground" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jheloper/rust-playground"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jheloper/rust-playground'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d85b4f696fa5a93150130f04a772761711c4d088
[INFO] sha for GitHub repo jheloper/rust-playground: d85b4f696fa5a93150130f04a772761711c4d088
[INFO] validating manifest of jheloper/rust-playground 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 jheloper/rust-playground 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 jheloper/rust-playground
[INFO] finished frobbing jheloper/rust-playground
[INFO] frobbed toml for jheloper/rust-playground written to work/ex/beta-1.38-1/sources/1.37.0/gh/jheloper/rust-playground/Cargo.toml
[INFO] started frobbing jheloper/rust-playground
[INFO] finished frobbing jheloper/rust-playground
[INFO] frobbed toml for jheloper/rust-playground written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/jheloper/rust-playground/Cargo.toml
[INFO] crate jheloper/rust-playground 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 jheloper/rust-playground 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-4/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/jheloper/rust-playground:/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] dcdc580bade95104fa36b19c4ae378c4d9c33494ce725c25d171f24c90759ef1
[INFO] running `"docker" "start" "-a" "dcdc580bade95104fa36b19c4ae378c4d9c33494ce725c25d171f24c90759ef1"`
[INFO] [stderr]    Compiling rust-playground v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:66:9
[INFO] [stderr]    |
[INFO] [stderr] 66 |     let x = 10;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.68s
[INFO] running `"docker" "inspect" "dcdc580bade95104fa36b19c4ae378c4d9c33494ce725c25d171f24c90759ef1"`
[INFO] running `"docker" "rm" "-f" "dcdc580bade95104fa36b19c4ae378c4d9c33494ce725c25d171f24c90759ef1"`
[INFO] [stdout] dcdc580bade95104fa36b19c4ae378c4d9c33494ce725c25d171f24c90759ef1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/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/jheloper/rust-playground:/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] d3f5003d950a71058f25226c55f0bea3e0f0188492b365ed502a90fdf80e79fc
[INFO] running `"docker" "start" "-a" "d3f5003d950a71058f25226c55f0bea3e0f0188492b365ed502a90fdf80e79fc"`
[INFO] [stderr]    Compiling rust-playground v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:66:9
[INFO] [stderr]    |
[INFO] [stderr] 66 |     let x = 10;
[INFO] [stderr]    |         ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.74s
[INFO] running `"docker" "inspect" "d3f5003d950a71058f25226c55f0bea3e0f0188492b365ed502a90fdf80e79fc"`
[INFO] running `"docker" "rm" "-f" "d3f5003d950a71058f25226c55f0bea3e0f0188492b365ed502a90fdf80e79fc"`
[INFO] [stdout] d3f5003d950a71058f25226c55f0bea3e0f0188492b365ed502a90fdf80e79fc
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-4/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/jheloper/rust-playground:/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] 6b266e2ec2d2d21fb98eb160ac978b1021a663bc41ba30d6ab90fd93c892706d
[INFO] running `"docker" "start" "-a" "6b266e2ec2d2d21fb98eb160ac978b1021a663bc41ba30d6ab90fd93c892706d"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running /opt/crater/target/debug/deps/rust_playground-4ea7b7396a35f0ec
[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" "6b266e2ec2d2d21fb98eb160ac978b1021a663bc41ba30d6ab90fd93c892706d"`
[INFO] running `"docker" "rm" "-f" "6b266e2ec2d2d21fb98eb160ac978b1021a663bc41ba30d6ab90fd93c892706d"`
[INFO] [stdout] 6b266e2ec2d2d21fb98eb160ac978b1021a663bc41ba30d6ab90fd93c892706d