[INFO] crate heapless 0.4.2 is already in cache
[INFO] extracting crate heapless 0.4.2 into work/ex/pr-60162/sources/master#a850a426491e14186af2250549bf41256b5938d2/reg/heapless/0.4.2
[INFO] extracting crate heapless 0.4.2 into work/ex/pr-60162/sources/try#06a150c7d11500b41499224f165e9de1de096768/reg/heapless/0.4.2
[INFO] validating manifest of heapless-0.4.2 on toolchain master#a850a426491e14186af2250549bf41256b5938d2
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+a850a426491e14186af2250549bf41256b5938d2-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of heapless-0.4.2 on toolchain try#06a150c7d11500b41499224f165e9de1de096768
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+06a150c7d11500b41499224f165e9de1de096768-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing heapless-0.4.2
[INFO] finished frobbing heapless-0.4.2
[INFO] frobbed toml for heapless-0.4.2 written to work/ex/pr-60162/sources/master#a850a426491e14186af2250549bf41256b5938d2/reg/heapless/0.4.2/Cargo.toml
[INFO] started frobbing heapless-0.4.2
[INFO] finished frobbing heapless-0.4.2
[INFO] frobbed toml for heapless-0.4.2 written to work/ex/pr-60162/sources/try#06a150c7d11500b41499224f165e9de1de096768/reg/heapless/0.4.2/Cargo.toml
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+a850a426491e14186af2250549bf41256b5938d2-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+06a150c7d11500b41499224f165e9de1de096768-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+a850a426491e14186af2250549bf41256b5938d2-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+06a150c7d11500b41499224f165e9de1de096768-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking heapless-0.4.2 against master#a850a426491e14186af2250549bf41256b5938d2 for pr-60162
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-60162/worker-0/master#a850a426491e14186af2250549bf41256b5938d2:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-60162/sources/master#a850a426491e14186af2250549bf41256b5938d2/reg/heapless/0.4.2:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/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" "+a850a426491e14186af2250549bf41256b5938d2-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 38c11f33d6516df06a05409feb819ac2f6ebbcd4b7cab94b45c50a8027d14907
[INFO] running `"docker" "start" "-a" "38c11f33d6516df06a05409feb819ac2f6ebbcd4b7cab94b45c50a8027d14907"`
[INFO] [stderr]     Checking heapless v0.4.2 (/opt/crater/workdir)
[INFO] [stderr] error: unused return value of `core::result::Result::<T, E>::is_ok` that must be used
[INFO] [stderr]    --> src/string.rs:782:9
[INFO] [stderr]     |
[INFO] [stderr] 782 |         s.push('1').is_ok();
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr] note: lint level defined here
[INFO] [stderr]    --> src/lib.rs:82:9
[INFO] [stderr]     |
[INFO] [stderr] 82  | #![deny(warnings)]
[INFO] [stderr]     |         ^^^^^^^^
[INFO] [stderr]     = note: #[deny(unused_must_use)] implied by #[deny(warnings)]
[INFO] [stderr] 
[INFO] [stderr] error: unused return value of `core::result::Result::<T, E>::is_ok` that must be used
[INFO] [stderr]    --> src/string.rs:783:9
[INFO] [stderr]     |
[INFO] [stderr] 783 |         s.push('2').is_ok();
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: unused return value of `core::result::Result::<T, E>::is_ok` that must be used
[INFO] [stderr]    --> src/string.rs:784:9
[INFO] [stderr]     |
[INFO] [stderr] 784 |         s.push('3').is_ok();
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: unused return value of `core::result::Result::<T, E>::is_err` that must be used
[INFO] [stderr]    --> src/string.rs:785:9
[INFO] [stderr]     |
[INFO] [stderr] 785 |         s.push('4').is_err();
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `heapless`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "38c11f33d6516df06a05409feb819ac2f6ebbcd4b7cab94b45c50a8027d14907"`
[INFO] running `"docker" "rm" "-f" "38c11f33d6516df06a05409feb819ac2f6ebbcd4b7cab94b45c50a8027d14907"`
[INFO] [stdout] 38c11f33d6516df06a05409feb819ac2f6ebbcd4b7cab94b45c50a8027d14907