Dec 12 01:38:11.772 INFO checking MainShayne233/concurrency_demo against try#aa9aa79c3c583aab59ac9134542d60a780c35e2e for pr-56677
Dec 12 01:38:11.772 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56677/worker-4/try#aa9aa79c3c583aab59ac9134542d60a780c35e2e:/target:rw,Z" "-v" "/mnt/big/crater/work/local/test-source/worker-4/pr-56677/try#aa9aa79c3c583aab59ac9134542d60a780c35e2e:/source:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/source" "-e" "USER_ID=1000" "-e" "CMD=cargo +aa9aa79c3c583aab59ac9134542d60a780c35e2e-alt check --frozen --all --all-targets" "-e" "CARGO_TARGET_DIR=/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/cargo-home" "-e" "RUSTUP_HOME=/rustup-home" "-m" "1536M" "--network" "none" "crater"`
Dec 12 01:38:12.008 INFO [stdout] bc67d24fe2f0144a309a1f8484cc92d054582aec00b1f9dd8f39bbbaed147c8d
Dec 12 01:38:12.010 INFO running `"docker" "start" "-a" "bc67d24fe2f0144a309a1f8484cc92d054582aec00b1f9dd8f39bbbaed147c8d"`
Dec 12 01:38:13.636 INFO [stderr] usermod: no changes
Dec 12 01:38:13.684 INFO [stderr]     Checking concurrency_demo v0.1.0 (/source)
Dec 12 01:38:14.496 INFO [stderr] warning: field is never used: `workers`
Dec 12 01:38:14.496 INFO [stderr]  --> src/lib.rs:7:5
Dec 12 01:38:14.496 INFO [stderr]   |
Dec 12 01:38:14.496 INFO [stderr] 7 |     workers: Vec<Worker>,
Dec 12 01:38:14.497 INFO [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
Dec 12 01:38:14.497 INFO [stderr]   |
Dec 12 01:38:14.497 INFO [stderr]   = note: #[warn(dead_code)] on by default
Dec 12 01:38:14.497 INFO [stderr] 
Dec 12 01:38:14.497 INFO [stderr] warning: field is never used: `id`
Dec 12 01:38:14.497 INFO [stderr]   --> src/lib.rs:49:5
Dec 12 01:38:14.497 INFO [stderr]    |
Dec 12 01:38:14.497 INFO [stderr] 49 |     id: usize,
Dec 12 01:38:14.497 INFO [stderr]    |     ^^^^^^^^^
Dec 12 01:38:14.497 INFO [stderr] 
Dec 12 01:38:14.497 INFO [stderr] warning: field is never used: `thread`
Dec 12 01:38:14.497 INFO [stderr]   --> src/lib.rs:50:5
Dec 12 01:38:14.497 INFO [stderr]    |
Dec 12 01:38:14.497 INFO [stderr] 50 |     thread: thread::JoinHandle<()>,
Dec 12 01:38:14.497 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 01:38:14.497 INFO [stderr] 
Dec 12 01:38:14.736 INFO [stderr] warning: field is never used: `workers`
Dec 12 01:38:14.736 INFO [stderr]  --> src/lib.rs:7:5
Dec 12 01:38:14.736 INFO [stderr]   |
Dec 12 01:38:14.736 INFO [stderr] 7 |     workers: Vec<Worker>,
Dec 12 01:38:14.736 INFO [stderr]   |     ^^^^^^^^^^^^^^^^^^^^
Dec 12 01:38:14.736 INFO [stderr]   |
Dec 12 01:38:14.736 INFO [stderr]   = note: #[warn(dead_code)] on by default
Dec 12 01:38:14.736 INFO [stderr] 
Dec 12 01:38:14.736 INFO [stderr] warning: field is never used: `id`
Dec 12 01:38:14.736 INFO [stderr]   --> src/lib.rs:49:5
Dec 12 01:38:14.736 INFO [stderr]    |
Dec 12 01:38:14.736 INFO [stderr] 49 |     id: usize,
Dec 12 01:38:14.736 INFO [stderr]    |     ^^^^^^^^^
Dec 12 01:38:14.736 INFO [stderr] 
Dec 12 01:38:14.736 INFO [stderr] warning: field is never used: `thread`
Dec 12 01:38:14.736 INFO [stderr]   --> src/lib.rs:50:5
Dec 12 01:38:14.736 INFO [stderr]    |
Dec 12 01:38:14.736 INFO [stderr] 50 |     thread: thread::JoinHandle<()>,
Dec 12 01:38:14.736 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 01:38:14.736 INFO [stderr] 
Dec 12 01:38:15.565 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.91s
Dec 12 01:38:15.567 INFO [stderr] su: No module specific data is present
Dec 12 01:38:16.466 INFO running `"docker" "inspect" "bc67d24fe2f0144a309a1f8484cc92d054582aec00b1f9dd8f39bbbaed147c8d"`
Dec 12 01:38:16.882 INFO running `"docker" "rm" "-f" "bc67d24fe2f0144a309a1f8484cc92d054582aec00b1f9dd8f39bbbaed147c8d"`
Dec 12 01:38:17.176 INFO [stdout] bc67d24fe2f0144a309a1f8484cc92d054582aec00b1f9dd8f39bbbaed147c8d