[INFO] updating cached repository Mancomb/four_in_a_row
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Mancomb/four_in_a_row
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Mancomb/four_in_a_row" "work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Mancomb/four_in_a_row"`
[INFO] [stderr] Cloning into 'work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Mancomb/four_in_a_row'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Mancomb/four_in_a_row" "work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Mancomb/four_in_a_row"`
[INFO] [stderr] Cloning into 'work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Mancomb/four_in_a_row'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 427c187f7c102753a490b6d0a96b1fa140787c9c
[INFO] sha for GitHub repo Mancomb/four_in_a_row: 427c187f7c102753a490b6d0a96b1fa140787c9c
[INFO] validating manifest of Mancomb/four_in_a_row 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 Mancomb/four_in_a_row 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 Mancomb/four_in_a_row
[INFO] finished frobbing Mancomb/four_in_a_row
[INFO] frobbed toml for Mancomb/four_in_a_row written to work/ex/pr-58948/sources/master#0f88167f89fffe321590c5148f21b7d51d44388d/gh/Mancomb/four_in_a_row/Cargo.toml
[INFO] started frobbing Mancomb/four_in_a_row
[INFO] finished frobbing Mancomb/four_in_a_row
[INFO] frobbed toml for Mancomb/four_in_a_row written to work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Mancomb/four_in_a_row/Cargo.toml
[INFO] crate Mancomb/four_in_a_row 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 Mancomb/four_in_a_row against try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b for pr-58948
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-58948/worker-2/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-58948/sources/try#a829e31f924ec11e400e8d0c2fd2c4bb8937ae6b/gh/Mancomb/four_in_a_row:/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] 095d04cedb4febda87315abdc5388164b4ed7d320e2c3155a9a225aff231a4c4
[INFO] running `"docker" "start" "-a" "095d04cedb4febda87315abdc5388164b4ed7d320e2c3155a9a225aff231a4c4"`
[INFO] [stderr]     Checking mcts v0.2.0
[INFO] [stderr]     Checking four_in_a_row v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `random::Random`
[INFO] [stderr]   --> src/main.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 | use random::Random;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `random::Random`
[INFO] [stderr]   --> src/main.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 | use random::Random;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Random`
[INFO] [stderr]  --> src/random.rs:8:1
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub struct Random;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:56:17
[INFO] [stderr]    |
[INFO] [stderr] 56 |                 write!(out, "|{}", c);
[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]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:58:13
[INFO] [stderr]    |
[INFO] [stderr] 58 |             writeln!(out, "|");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:60:9
[INFO] [stderr]    |
[INFO] [stderr] 60 |         writeln!(out, "---------------\n 0 1 2 3 4 5 6");
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Random`
[INFO] [stderr]  --> src/random.rs:8:1
[INFO] [stderr]   |
[INFO] [stderr] 8 | pub struct Random;
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:56:17
[INFO] [stderr]    |
[INFO] [stderr] 56 |                 write!(out, "|{}", c);
[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]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:58:13
[INFO] [stderr]    |
[INFO] [stderr] 58 |             writeln!(out, "|");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]   --> src/connect_four.rs:60:9
[INFO] [stderr]    |
[INFO] [stderr] 60 |         writeln!(out, "---------------\n 0 1 2 3 4 5 6");
[INFO] [stderr]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr]    = note: this error originates in a macro outside of the current crate (in Nightly builds, run with -Z external-macro-backtrace for more info)
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.83s
[INFO] running `"docker" "inspect" "095d04cedb4febda87315abdc5388164b4ed7d320e2c3155a9a225aff231a4c4"`
[INFO] running `"docker" "rm" "-f" "095d04cedb4febda87315abdc5388164b4ed7d320e2c3155a9a225aff231a4c4"`
[INFO] [stdout] 095d04cedb4febda87315abdc5388164b4ed7d320e2c3155a9a225aff231a4c4