Dec 12 13:15:37.798 INFO checking hindley-milner-0.1.0 against master#3a75e80557a103497cffbcab395a2f37061a77ea for pr-56677
Dec 12 13:15:37.798 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56677/worker-4/master#3a75e80557a103497cffbcab395a2f37061a77ea:/target:rw,Z" "-v" "/mnt/big/crater/work/local/test-source/worker-4/pr-56677/master#3a75e80557a103497cffbcab395a2f37061a77ea:/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 +3a75e80557a103497cffbcab395a2f37061a77ea-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 13:15:38.104 INFO [stdout] 46580f0e8c4f8c9b7752d0566bb1d30aff3e934bccabed3f249a5a3d5337a68e
Dec 12 13:15:38.106 INFO running `"docker" "start" "-a" "46580f0e8c4f8c9b7752d0566bb1d30aff3e934bccabed3f249a5a3d5337a68e"`
Dec 12 13:15:38.594 INFO [stderr] usermod: no changes
Dec 12 13:15:38.642 INFO [stderr]     Checking hindley-milner v0.1.0 (/source)
Dec 12 13:15:39.416 INFO [stderr] warning: struct is never constructed: `Namer`
Dec 12 13:15:39.416 INFO [stderr]   --> src/lib.rs:77:1
Dec 12 13:15:39.416 INFO [stderr]    |
Dec 12 13:15:39.416 INFO [stderr] 77 | struct Namer {
Dec 12 13:15:39.416 INFO [stderr]    | ^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr]    |
Dec 12 13:15:39.416 INFO [stderr]    = note: #[warn(dead_code)] on by default
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.416 INFO [stderr] warning: method is never used: `next`
Dec 12 13:15:39.416 INFO [stderr]   --> src/lib.rs:83:5
Dec 12 13:15:39.416 INFO [stderr]    |
Dec 12 13:15:39.416 INFO [stderr] 83 |     fn next(&mut self) -> String {
Dec 12 13:15:39.416 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.416 INFO [stderr] warning: method is never used: `name`
Dec 12 13:15:39.416 INFO [stderr]   --> src/lib.rs:89:5
Dec 12 13:15:39.416 INFO [stderr]    |
Dec 12 13:15:39.416 INFO [stderr] 89 |     fn name(&mut self, t: ArenaType) -> String {
Dec 12 13:15:39.416 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.416 INFO [stderr] warning: method is never used: `id`
Dec 12 13:15:39.416 INFO [stderr]    --> src/lib.rs:124:5
Dec 12 13:15:39.416 INFO [stderr]     |
Dec 12 13:15:39.416 INFO [stderr] 124 |     fn id(&self) -> usize {
Dec 12 13:15:39.416 INFO [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.416 INFO [stderr] warning: method is never used: `as_string`
Dec 12 13:15:39.416 INFO [stderr]    --> src/lib.rs:146:5
Dec 12 13:15:39.416 INFO [stderr]     |
Dec 12 13:15:39.416 INFO [stderr] 146 |     fn as_string(&self, a: &Vec<Type>, namer: &mut Namer) -> String {
Dec 12 13:15:39.416 INFO [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.416 INFO [stderr] warning: function is never used: `test_env`
Dec 12 13:15:39.416 INFO [stderr]    --> src/lib.rs:537:1
Dec 12 13:15:39.416 INFO [stderr]     |
Dec 12 13:15:39.416 INFO [stderr] 537 | fn test_env() -> (Vec<Type>, Env) {
Dec 12 13:15:39.416 INFO [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 12 13:15:39.416 INFO [stderr] 
Dec 12 13:15:39.483 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.86s
Dec 12 13:15:39.485 INFO [stderr] su: No module specific data is present
Dec 12 13:15:39.916 INFO running `"docker" "inspect" "46580f0e8c4f8c9b7752d0566bb1d30aff3e934bccabed3f249a5a3d5337a68e"`
Dec 12 13:15:40.244 INFO running `"docker" "rm" "-f" "46580f0e8c4f8c9b7752d0566bb1d30aff3e934bccabed3f249a5a3d5337a68e"`
Dec 12 13:15:40.562 INFO [stdout] 46580f0e8c4f8c9b7752d0566bb1d30aff3e934bccabed3f249a5a3d5337a68e