[INFO] fetching crate arbitrator 0.1.3...
[INFO] checking arbitrator-0.1.3 against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] extracting crate arbitrator 0.1.3 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate arbitrator 0.1.3 on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arbitrator 0.1.3
[INFO] finished tweaking crates.io crate arbitrator 0.1.3
[INFO] tweaked toml for crates.io crate arbitrator 0.1.3 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate crates.io crate arbitrator 0.1.3 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded unicode-width v0.1.8
[INFO] [stderr]   Downloaded structopt v0.3.22
[INFO] [stderr]   Downloaded quote v1.0.9
[INFO] [stderr]   Downloaded structopt-derive v0.4.15
[INFO] [stderr]   Downloaded itoa v0.4.7
[INFO] [stderr]   Downloaded proc-macro2 v1.0.28
[INFO] [stderr]   Downloaded memchr v2.4.0
[INFO] [stderr]   Downloaded itertools v0.10.1
[INFO] [stderr]   Downloaded serde v1.0.127
[INFO] [stderr]   Downloaded syn v1.0.74
[INFO] [stderr]   Downloaded libc v0.2.98
[INFO] [stderr]   Downloaded serde_json v1.0.66
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e1bfd1fa5bed471dfad1e7a15bcf80e66c8479bf127721428ed60e6e3bfd5f5c
[INFO] running `Command { std: "docker" "start" "-a" "e1bfd1fa5bed471dfad1e7a15bcf80e66c8479bf127721428ed60e6e3bfd5f5c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e1bfd1fa5bed471dfad1e7a15bcf80e66c8479bf127721428ed60e6e3bfd5f5c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1bfd1fa5bed471dfad1e7a15bcf80e66c8479bf127721428ed60e6e3bfd5f5c", kill_on_drop: false }`
[INFO] [stdout] e1bfd1fa5bed471dfad1e7a15bcf80e66c8479bf127721428ed60e6e3bfd5f5c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cbfa6abb187988043e5078f91d5b616dc9a483f2af4f1c3b41d3291354fdd1c9
[INFO] running `Command { std: "docker" "start" "-a" "cbfa6abb187988043e5078f91d5b616dc9a483f2af4f1c3b41d3291354fdd1c9", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking itertools v0.10.1
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]    Compiling structopt-derive v0.4.15
[INFO] [stderr]     Checking structopt v0.3.22
[INFO] [stderr]     Checking arbitrator v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait `NextN` is never used
[INFO] [stdout]   --> src/main.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait NextN {
[INFO] [stdout]    |       ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `NextN` is never used
[INFO] [stdout]   --> src/main.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait NextN {
[INFO] [stdout]    |       ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.50s
[INFO] running `Command { std: "docker" "inspect" "cbfa6abb187988043e5078f91d5b616dc9a483f2af4f1c3b41d3291354fdd1c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cbfa6abb187988043e5078f91d5b616dc9a483f2af4f1c3b41d3291354fdd1c9", kill_on_drop: false }`
[INFO] [stdout] cbfa6abb187988043e5078f91d5b616dc9a483f2af4f1c3b41d3291354fdd1c9
[INFO] checking arbitrator-0.1.3 against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] extracting crate arbitrator 0.1.3 into /workspace/builds/worker-4-tc2/source
[INFO] validating manifest of crates.io crate arbitrator 0.1.3 on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate arbitrator 0.1.3
[INFO] finished tweaking crates.io crate arbitrator 0.1.3
[INFO] tweaked toml for crates.io crate arbitrator 0.1.3 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate crates.io crate arbitrator 0.1.3 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e5180996ed344fd49e34520a27917328e0c2a5f316cb7737f26be4ae157ff1a7
[INFO] running `Command { std: "docker" "start" "-a" "e5180996ed344fd49e34520a27917328e0c2a5f316cb7737f26be4ae157ff1a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e5180996ed344fd49e34520a27917328e0c2a5f316cb7737f26be4ae157ff1a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e5180996ed344fd49e34520a27917328e0c2a5f316cb7737f26be4ae157ff1a7", kill_on_drop: false }`
[INFO] [stdout] e5180996ed344fd49e34520a27917328e0c2a5f316cb7737f26be4ae157ff1a7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 12798fb3332a2e25d0adbab84116da5281a8caaebf4b919ba30f42902a78392b
[INFO] running `Command { std: "docker" "start" "-a" "12798fb3332a2e25d0adbab84116da5281a8caaebf4b919ba30f42902a78392b", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking itertools v0.10.1
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]    Compiling structopt-derive v0.4.15
[INFO] [stderr]     Checking structopt v0.3.22
[INFO] [stderr]     Checking arbitrator v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait `NextN` is never used
[INFO] [stdout]   --> src/main.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait NextN {
[INFO] [stdout]    |       ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait `NextN` is never used
[INFO] [stdout]   --> src/main.rs:13:7
[INFO] [stdout]    |
[INFO] [stdout] 13 | trait NextN {
[INFO] [stdout]    |       ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 4.39s
[INFO] running `Command { std: "docker" "inspect" "12798fb3332a2e25d0adbab84116da5281a8caaebf4b919ba30f42902a78392b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12798fb3332a2e25d0adbab84116da5281a8caaebf4b919ba30f42902a78392b", kill_on_drop: false }`
[INFO] [stdout] 12798fb3332a2e25d0adbab84116da5281a8caaebf4b919ba30f42902a78392b