[INFO] fetching crate r4 1.0.1...
[INFO] extracting crate r4 1.0.1 into work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/reg/r4/1.0.1
[INFO] extracting crate r4 1.0.1 into work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/reg/r4/1.0.1
[INFO] validating manifest of r4-1.0.1 on toolchain master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of r4-1.0.1 on toolchain try#8f81d0bf6baf07b92f1246696722485c4ca0b049
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing r4-1.0.1
[INFO] finished frobbing r4-1.0.1
[INFO] frobbed toml for r4-1.0.1 written to work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/reg/r4/1.0.1/Cargo.toml
[INFO] started frobbing r4-1.0.1
[INFO] finished frobbing r4-1.0.1
[INFO] frobbed toml for r4-1.0.1 written to work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/reg/r4/1.0.1/Cargo.toml
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking r4-1.0.1 against master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1 for pr-62008
[INFO] running `"docker" "create" "-v" "/mnt/big/ec2-user/crater/work/local/target-dirs/pr-62008/worker-1/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1:/opt/crater/target:rw,Z" "-v" "/mnt/big/ec2-user/crater/work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/reg/r4/1.0.1:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/ec2-user/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" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 836802893cacdf662296ccdf94ff17118ca615cc5fce9cc12099f17a69e7700d
[INFO] running `"docker" "start" "-a" "836802893cacdf662296ccdf94ff17118ca615cc5fce9cc12099f17a69e7700d"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking r4 v1.0.1 (/opt/crater/workdir)
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]    --> src/lib.rs:407:34
[INFO] [stderr]     |
[INFO] [stderr] 407 |                     iterate![for i in 0..4;
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_i`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]    --> src/lib.rs:433:34
[INFO] [stderr]     |
[INFO] [stderr] 433 |                     iterate![for x in vs.iter();
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]    --> src/lib.rs:443:34
[INFO] [stderr]     |
[INFO] [stderr] 443 |                     iterate![for x in vs.iter();
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/lib.rs:474:34
[INFO] [stderr]     |
[INFO] [stderr] 474 |                              let a = *x + 3;
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/lib.rs:489:34
[INFO] [stderr]     |
[INFO] [stderr] 489 |                              let a = *x + 3;
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_a`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `y`
[INFO] [stderr]    --> src/lib.rs:506:34
[INFO] [stderr]     |
[INFO] [stderr] 506 |                              for y in vs.iter();
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_y`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]    --> src/lib.rs:522:34
[INFO] [stderr]     |
[INFO] [stderr] 522 |                              let x = *x + 1;
[INFO] [stderr]     |                                  ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.86s
[INFO] running `"docker" "inspect" "836802893cacdf662296ccdf94ff17118ca615cc5fce9cc12099f17a69e7700d"`
[INFO] running `"docker" "rm" "-f" "836802893cacdf662296ccdf94ff17118ca615cc5fce9cc12099f17a69e7700d"`
[INFO] [stdout] 836802893cacdf662296ccdf94ff17118ca615cc5fce9cc12099f17a69e7700d