[INFO] updating cached repository Cackbone/2048.rs
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Cackbone/2048.rs
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Cackbone/2048.rs" "work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Cackbone/2048.rs"`
[INFO] [stderr] Cloning into 'work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Cackbone/2048.rs'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Cackbone/2048.rs" "work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Cackbone/2048.rs"`
[INFO] [stderr] Cloning into 'work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Cackbone/2048.rs'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9c58e9f2ea5fb12a56dd27087d6b618184fc8c6f
[INFO] sha for GitHub repo Cackbone/2048.rs: 9c58e9f2ea5fb12a56dd27087d6b618184fc8c6f
[INFO] validating manifest of Cackbone/2048.rs on toolchain master#0f88167f89fffe321590c5148f21b7d51d44388d
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0f88167f89fffe321590c5148f21b7d51d44388d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Cackbone/2048.rs on toolchain try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing Cackbone/2048.rs
[INFO] finished frobbing Cackbone/2048.rs
[INFO] frobbed toml for Cackbone/2048.rs written to work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Cackbone/2048.rs/Cargo.toml
[INFO] started frobbing Cackbone/2048.rs
[INFO] finished frobbing Cackbone/2048.rs
[INFO] frobbed toml for Cackbone/2048.rs written to work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Cackbone/2048.rs/Cargo.toml
[INFO] crate Cackbone/2048.rs already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+0f88167f89fffe321590c5148f21b7d51d44388d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking Cackbone/2048.rs against try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b for pr-58948
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58948/worker-7/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Cackbone/2048.rs:/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" "+a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 29d262dbfd3fd8350cd82efc5db12703d9fda7e1b39df232ab8d9a956ca859c5
[INFO] running `"docker" "start" "-a" "29d262dbfd3fd8350cd82efc5db12703d9fda7e1b39df232ab8d9a956ca859c5"`
[INFO] [stderr]     Checking rust_2048 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: value assigned to `grid_bis` is never read
[INFO] [stderr]   --> src/main.rs:18:13
[INFO] [stderr]    |
[INFO] [stderr] 18 |     let mut grid_bis = [[0i8; 4];4];
[INFO] [stderr]    |             ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:97:28
[INFO] [stderr]    |
[INFO] [stderr] 97 | fn move_grid(d: Direction, mut grid: &mut [[i8; 4]; 4])
[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] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:137:13
[INFO] [stderr]     |
[INFO] [stderr] 137 | fn add_tile(mut grid: &mut [[i8; 4]; 4])
[INFO] [stderr]     |             ----^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:52:13
[INFO] [stderr]    |
[INFO] [stderr] 52 |             Command::new("clear").status();
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     Command::new("clear").status();
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: value assigned to `grid_bis` is never read
[INFO] [stderr]   --> src/main.rs:18:13
[INFO] [stderr]    |
[INFO] [stderr] 18 |     let mut grid_bis = [[0i8; 4];4];
[INFO] [stderr]    |             ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_assignments)] on by default
[INFO] [stderr]    = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:97:28
[INFO] [stderr]    |
[INFO] [stderr] 97 | fn move_grid(d: Direction, mut grid: &mut [[i8; 4]; 4])
[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] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:137:13
[INFO] [stderr]     |
[INFO] [stderr] 137 | fn add_tile(mut grid: &mut [[i8; 4]; 4])
[INFO] [stderr]     |             ----^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:52:13
[INFO] [stderr]    |
[INFO] [stderr] 52 |             Command::new("clear").status();
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/main.rs:75:5
[INFO] [stderr]    |
[INFO] [stderr] 75 |     Command::new("clear").status();
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.98s
[INFO] running `"docker" "inspect" "29d262dbfd3fd8350cd82efc5db12703d9fda7e1b39df232ab8d9a956ca859c5"`
[INFO] running `"docker" "rm" "-f" "29d262dbfd3fd8350cd82efc5db12703d9fda7e1b39df232ab8d9a956ca859c5"`
[INFO] [stdout] 29d262dbfd3fd8350cd82efc5db12703d9fda7e1b39df232ab8d9a956ca859c5