[INFO] cloning repository https://github.com/Licenser/task-thread-cmp
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Licenser/task-thread-cmp" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLicenser%2Ftask-thread-cmp", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLicenser%2Ftask-thread-cmp'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a1472ce0903e70a1d810d249ac95cc21cbaabc08
[INFO] checking Licenser/task-thread-cmp against master#4fb54ed484e2239a3e9eff3be17df00d2a162be3 for pr-73345
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLicenser%2Ftask-thread-cmp" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Licenser/task-thread-cmp on toolchain 4fb54ed484e2239a3e9eff3be17df00d2a162be3
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Licenser/task-thread-cmp
[INFO] finished tweaking git repo https://github.com/Licenser/task-thread-cmp
[INFO] tweaked toml for git repo https://github.com/Licenser/task-thread-cmp written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/Licenser/task-thread-cmp already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 34f846afc6b0242bb31da11aac7471bc134fc95f4a6e24ac9224eb3712083ce3
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "34f846afc6b0242bb31da11aac7471bc134fc95f4a6e24ac9224eb3712083ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "34f846afc6b0242bb31da11aac7471bc134fc95f4a6e24ac9224eb3712083ce3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34f846afc6b0242bb31da11aac7471bc134fc95f4a6e24ac9224eb3712083ce3", kill_on_drop: false }`
[INFO] [stdout] 34f846afc6b0242bb31da11aac7471bc134fc95f4a6e24ac9224eb3712083ce3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:6c9ffe128752d56c8d75334ed354142a5229917ed99767f56566dd8e857ad726" "/opt/rustwide/cargo-home/bin/cargo" "+4fb54ed484e2239a3e9eff3be17df00d2a162be3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2d232c32b8e3880f0d27925b3d4350df5fe31a8a03aeced66b228e5320d6558b
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "2d232c32b8e3880f0d27925b3d4350df5fe31a8a03aeced66b228e5320d6558b", kill_on_drop: false }`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling proc-macro2 v1.0.9
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling syn v1.0.16
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]     Checking futures-core v0.3.4
[INFO] [stderr]     Checking futures-sink v0.3.4
[INFO] [stderr]     Checking smallvec v1.2.0
[INFO] [stderr]     Checking futures-task v0.3.4
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking futures-io v0.3.4
[INFO] [stderr]     Checking pin-project-lite v0.1.4
[INFO] [stderr]     Checking once_cell v1.3.1
[INFO] [stderr]     Checking futures-timer v2.0.2
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking lock_api v0.3.3
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking kv-log-macro v1.0.4
[INFO] [stderr]     Checking crossbeam-channel v0.4.2
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]     Checking parking_lot_core v0.7.0
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking num_cpus v1.12.0
[INFO] [stderr]     Checking async-task v1.3.1
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking parking_lot v0.10.0
[INFO] [stderr]     Checking crossbeam-deque v0.7.3
[INFO] [stderr]     Checking mio-uds v0.6.7
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]     Checking futures-util v0.3.4
[INFO] [stderr]     Checking broadcaster v1.0.0
[INFO] [stderr]     Checking async-std v1.5.0
[INFO] [stderr]     Checking task-thread-cmp v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/threads.rs:16:13
[INFO] [stdout]    |
[INFO] [stdout] 16 |             tx1.send(x - 2);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/threads.rs:22:13
[INFO] [stdout]    |
[INFO] [stdout] 22 |             tx2.send(i);
[INFO] [stdout]    |             ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/threads.rs:16:13
[INFO] [stdout]    |
[INFO] [stdout] 16 |             tx1.send(x - 2);
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> src/threads.rs:22:13
[INFO] [stdout]    |
[INFO] [stdout] 22 |             tx2.send(i);
[INFO] [stdout]    |             ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 42.73s
[INFO] running `Command { std: "docker" "inspect" "2d232c32b8e3880f0d27925b3d4350df5fe31a8a03aeced66b228e5320d6558b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2d232c32b8e3880f0d27925b3d4350df5fe31a8a03aeced66b228e5320d6558b", kill_on_drop: false }`
[INFO] [stdout] 2d232c32b8e3880f0d27925b3d4350df5fe31a8a03aeced66b228e5320d6558b