Dec 19 14:15:06.568 INFO checking kk1fff/backprop against master#d99a320cba42f661aebfa1293b7b2ec3603dda75 for pr-56955
Dec 19 14:15:06.568 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56955/worker-1/master#d99a320cba42f661aebfa1293b7b2ec3603dda75:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/gh/kk1fff/backprop:/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" "+d99a320cba42f661aebfa1293b7b2ec3603dda75-alt" "check" "--frozen" "--all" "--all-targets"`
Dec 19 14:15:06.746 INFO [stdout] a2dab329966c9ae689c5d47947ecc9dcfd8d09698cedb7008ae5c9d9dd39ec9d
Dec 19 14:15:06.749 INFO running `"docker" "start" "-a" "a2dab329966c9ae689c5d47947ecc9dcfd8d09698cedb7008ae5c9d9dd39ec9d"`
Dec 19 14:15:07.511 INFO [stderr]     Checking backprop v0.1.0 (/opt/crater/workdir)
Dec 19 14:15:07.720 INFO [stderr] warning: field is never used: `name`
Dec 19 14:15:07.720 INFO [stderr]   --> src/main.rs:46:5
Dec 19 14:15:07.720 INFO [stderr]    |
Dec 19 14:15:07.720 INFO [stderr] 46 |     name: String,
Dec 19 14:15:07.720 INFO [stderr]    |     ^^^^^^^^^^^^
Dec 19 14:15:07.720 INFO [stderr]    |
Dec 19 14:15:07.720 INFO [stderr]    = note: #[warn(dead_code)] on by default
Dec 19 14:15:07.720 INFO [stderr] 
Dec 19 14:15:07.720 INFO [stderr] warning: field is never used: `name`
Dec 19 14:15:07.720 INFO [stderr]   --> src/main.rs:93:5
Dec 19 14:15:07.720 INFO [stderr]    |
Dec 19 14:15:07.720 INFO [stderr] 93 |     name: String,
Dec 19 14:15:07.720 INFO [stderr]    |     ^^^^^^^^^^^^
Dec 19 14:15:07.720 INFO [stderr] 
Dec 19 14:15:07.720 INFO [stderr] warning: field is never used: `op_set`
Dec 19 14:15:07.720 INFO [stderr]   --> src/main.rs:94:5
Dec 19 14:15:07.720 INFO [stderr]    |
Dec 19 14:15:07.720 INFO [stderr] 94 |     op_set: HashSet<String>,
Dec 19 14:15:07.720 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
Dec 19 14:15:07.720 INFO [stderr] 
Dec 19 14:15:07.732 INFO [stderr] warning: field is never used: `name`
Dec 19 14:15:07.732 INFO [stderr]   --> src/main.rs:46:5
Dec 19 14:15:07.732 INFO [stderr]    |
Dec 19 14:15:07.732 INFO [stderr] 46 |     name: String,
Dec 19 14:15:07.732 INFO [stderr]    |     ^^^^^^^^^^^^
Dec 19 14:15:07.732 INFO [stderr]    |
Dec 19 14:15:07.732 INFO [stderr]    = note: #[warn(dead_code)] on by default
Dec 19 14:15:07.732 INFO [stderr] 
Dec 19 14:15:07.732 INFO [stderr] warning: field is never used: `name`
Dec 19 14:15:07.732 INFO [stderr]   --> src/main.rs:93:5
Dec 19 14:15:07.732 INFO [stderr]    |
Dec 19 14:15:07.732 INFO [stderr] 93 |     name: String,
Dec 19 14:15:07.732 INFO [stderr]    |     ^^^^^^^^^^^^
Dec 19 14:15:07.732 INFO [stderr] 
Dec 19 14:15:07.732 INFO [stderr] warning: field is never used: `op_set`
Dec 19 14:15:07.732 INFO [stderr]   --> src/main.rs:94:5
Dec 19 14:15:07.732 INFO [stderr]    |
Dec 19 14:15:07.732 INFO [stderr] 94 |     op_set: HashSet<String>,
Dec 19 14:15:07.732 INFO [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^
Dec 19 14:15:07.732 INFO [stderr] 
Dec 19 14:15:07.752 INFO [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.25s
Dec 19 14:15:08.002 INFO running `"docker" "inspect" "a2dab329966c9ae689c5d47947ecc9dcfd8d09698cedb7008ae5c9d9dd39ec9d"`
Dec 19 14:15:08.085 INFO running `"docker" "rm" "-f" "a2dab329966c9ae689c5d47947ecc9dcfd8d09698cedb7008ae5c9d9dd39ec9d"`
Dec 19 14:15:08.176 INFO [stdout] a2dab329966c9ae689c5d47947ecc9dcfd8d09698cedb7008ae5c9d9dd39ec9d