[INFO] cloning repository https://github.com/wzhd/ustcp
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/wzhd/ustcp" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwzhd%2Fustcp", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwzhd%2Fustcp'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 915bda49ce7fd7f9ba9e265aa53aa235fabf895e
[INFO] checking wzhd/ustcp against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwzhd%2Fustcp" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/wzhd/ustcp on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/wzhd/ustcp
[INFO] finished tweaking git repo https://github.com/wzhd/ustcp
[INFO] tweaked toml for git repo https://github.com/wzhd/ustcp written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/wzhd/ustcp already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 87ab91c1ff4a892d46b5dcbcb4f285e2999271c91dceb6271a9cfac84881b985
[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" "87ab91c1ff4a892d46b5dcbcb4f285e2999271c91dceb6271a9cfac84881b985", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "87ab91c1ff4a892d46b5dcbcb4f285e2999271c91dceb6271a9cfac84881b985", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "87ab91c1ff4a892d46b5dcbcb4f285e2999271c91dceb6271a9cfac84881b985", kill_on_drop: false }`
[INFO] [stdout] 87ab91c1ff4a892d46b5dcbcb4f285e2999271c91dceb6271a9cfac84881b985
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 5a30615f26de9903c7b87bfff450930617f73130186a6a94da7d4c38c459b471
[INFO] running `Command { std: "docker" "start" "-a" "5a30615f26de9903c7b87bfff450930617f73130186a6a94da7d4c38c459b471", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.18
[INFO] [stderr]     Checking regex-syntax v0.6.17
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking smallvec v1.4.0
[INFO] [stderr]     Checking termcolor v1.1.0
[INFO] [stderr]     Checking managed v0.7.1
[INFO] [stderr]     Checking matches v0.1.8
[INFO] [stderr]    Compiling cc v1.0.52
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]    Compiling serde v1.0.106
[INFO] [stderr]     Checking fnv v1.0.6
[INFO] [stderr]     Checking ioctl-sys v0.5.2
[INFO] [stderr]     Checking trilock v0.1.0 (https://github.com/wzhd/trilock.git#dc5b657f)
[INFO] [stderr]     Checking tracing-core v0.1.10
[INFO] [stderr]     Checking sharded-slab v0.0.9
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]     Checking futures-channel v0.3.4
[INFO] [stderr]     Checking unicode-bidi v0.3.4
[INFO] [stderr]    Compiling proc-macro2 v1.0.10
[INFO] [stderr]     Checking unicode-normalization v0.1.12
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]     Checking tracing-log v0.1.1
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]    Compiling backtrace-sys v0.1.36
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking smoltcp v0.6.0 (/opt/rustwide/workdir/ustcp)
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking time v0.1.43
[INFO] [stderr]     Checking idna v0.1.5
[INFO] [stderr]     Checking mio v0.6.21
[INFO] [stderr]     Checking url v1.7.2
[INFO] [stderr]     Checking chrono v0.4.11
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]     Checking backtrace v0.3.46
[INFO] [stderr]     Checking error-chain v0.11.0
[INFO] [stderr]     Checking regex v1.3.7
[INFO] [stderr]     Checking regex-automata v0.1.9
[INFO] [stderr]     Checking tun v0.4.4
[INFO] [stderr]     Checking matchers v0.0.1
[INFO] [stdout] error: unused return value of `core::mem::replace` that must be used
[INFO] [stdout]    --> ustcp/src/iface/neighbor.rs:107:21
[INFO] [stdout]     |
[INFO] [stdout] 107 |                     mem::replace(map, new_btree_map);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> ustcp/src/lib.rs:4:98
[INFO] [stdout]     |
[INFO] [stdout] 4   | #![cfg_attr(all(any(feature = "proto-ipv4", feature = "proto-ipv6"), feature = "ethernet"), deny(unused))]
[INFO] [stdout]     |                                                                                                  ^^^^^^
[INFO] [stdout]     = note: `#[deny(unused_must_use)]` implied by `#[deny(unused)]`
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smoltcp`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "5a30615f26de9903c7b87bfff450930617f73130186a6a94da7d4c38c459b471", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5a30615f26de9903c7b87bfff450930617f73130186a6a94da7d4c38c459b471", kill_on_drop: false }`
[INFO] [stdout] 5a30615f26de9903c7b87bfff450930617f73130186a6a94da7d4c38c459b471