[INFO] updating cached repository LiteUnder/learning-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/LiteUnder/learning-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/LiteUnder/learning-rust" "work/ex/beta-1.37-6/sources/1.36.0/gh/LiteUnder/learning-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/1.36.0/gh/LiteUnder/learning-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/LiteUnder/learning-rust" "work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/LiteUnder/learning-rust"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/LiteUnder/learning-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e78674640c5fcbbb9d090ab694fd270aae9adc20
[INFO] sha for GitHub repo LiteUnder/learning-rust: e78674640c5fcbbb9d090ab694fd270aae9adc20
[INFO] validating manifest of LiteUnder/learning-rust 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 LiteUnder/learning-rust 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 LiteUnder/learning-rust
[INFO] finished frobbing LiteUnder/learning-rust
[INFO] frobbed toml for LiteUnder/learning-rust written to work/ex/beta-1.37-6/sources/1.36.0/gh/LiteUnder/learning-rust/Cargo.toml
[INFO] started frobbing LiteUnder/learning-rust
[INFO] finished frobbing LiteUnder/learning-rust
[INFO] frobbed toml for LiteUnder/learning-rust written to work/ex/beta-1.37-6/sources/beta-2019-07-23/gh/LiteUnder/learning-rust/Cargo.toml
[INFO] crate LiteUnder/learning-rust 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] [stderr]     Blocking waiting for file lock on package cache lock
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-07-23" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing LiteUnder/learning-rust 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-1/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/LiteUnder/learning-rust:/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] de815c2cfb1efb2ba8920e430c2165cc20bae4da56fb4850f068e790b4e5b00a
[INFO] running `"docker" "start" "-a" "de815c2cfb1efb2ba8920e430c2165cc20bae4da56fb4850f068e790b4e5b00a"`
[INFO] [stderr]    Compiling testing v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:127:13
[INFO] [stderr]     |
[INFO] [stderr] 127 |         let mut s = String::from("yeah so that happened");
[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 1.70s
[INFO] running `"docker" "inspect" "de815c2cfb1efb2ba8920e430c2165cc20bae4da56fb4850f068e790b4e5b00a"`
[INFO] running `"docker" "rm" "-f" "de815c2cfb1efb2ba8920e430c2165cc20bae4da56fb4850f068e790b4e5b00a"`
[INFO] [stdout] de815c2cfb1efb2ba8920e430c2165cc20bae4da56fb4850f068e790b4e5b00a
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-1/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/LiteUnder/learning-rust:/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] d92ab9eac7952d3072dbafd7d0b2dea8a192b59e1da7ad6598a32fbe33385614
[INFO] running `"docker" "start" "-a" "d92ab9eac7952d3072dbafd7d0b2dea8a192b59e1da7ad6598a32fbe33385614"`
[INFO] [stderr]    Compiling testing v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:127:13
[INFO] [stderr]     |
[INFO] [stderr] 127 |         let mut s = String::from("yeah so that happened");
[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 1.01s
[INFO] running `"docker" "inspect" "d92ab9eac7952d3072dbafd7d0b2dea8a192b59e1da7ad6598a32fbe33385614"`
[INFO] running `"docker" "rm" "-f" "d92ab9eac7952d3072dbafd7d0b2dea8a192b59e1da7ad6598a32fbe33385614"`
[INFO] [stdout] d92ab9eac7952d3072dbafd7d0b2dea8a192b59e1da7ad6598a32fbe33385614
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.37-6/worker-1/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/LiteUnder/learning-rust:/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] 6bb69a0139a9d9ca3e9a98e41d243f22d38867fe2cc152ec9769d34e678f2dca
[INFO] running `"docker" "start" "-a" "6bb69a0139a9d9ca3e9a98e41d243f22d38867fe2cc152ec9769d34e678f2dca"`
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/crater/target/debug/deps/testing-cd08c9fd07addb84
[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" "6bb69a0139a9d9ca3e9a98e41d243f22d38867fe2cc152ec9769d34e678f2dca"`
[INFO] running `"docker" "rm" "-f" "6bb69a0139a9d9ca3e9a98e41d243f22d38867fe2cc152ec9769d34e678f2dca"`
[INFO] [stdout] 6bb69a0139a9d9ca3e9a98e41d243f22d38867fe2cc152ec9769d34e678f2dca