[INFO] fetching crate routeros_rust 0.0.21...
[INFO] checking routeros_rust-0.0.21 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate routeros_rust 0.0.21 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate routeros_rust 0.0.21 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate routeros_rust 0.0.21
[INFO] finished tweaking crates.io crate routeros_rust 0.0.21
[INFO] tweaked toml for crates.io crate routeros_rust 0.0.21 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 16 packages
[INFO] [stderr]       Adding rand v0.3.23 (latest: v0.8.5)
[INFO] [stderr]       Adding rand v0.4.6 (latest: v0.8.5)
[INFO] [stderr]       Adding rand_core v0.3.1 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_core v0.4.2 (latest: v0.6.4)
[INFO] [stderr]       Adding rdrand v0.4.0 (latest: v0.8.3)
[INFO] [stderr]       Adding time v0.1.45 (latest: v0.3.34)
[INFO] [stderr]       Adding wasi v0.10.0+wasi-snapshot-preview1 (latest: v0.13.0+wasi-0.2.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5fb888e666250161ad9812b38718f428a2bac7cc5bfd518c7d9b339906a873e9
[INFO] running `Command { std: "docker" "start" "-a" "5fb888e666250161ad9812b38718f428a2bac7cc5bfd518c7d9b339906a873e9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5fb888e666250161ad9812b38718f428a2bac7cc5bfd518c7d9b339906a873e9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5fb888e666250161ad9812b38718f428a2bac7cc5bfd518c7d9b339906a873e9", kill_on_drop: false }`
[INFO] [stdout] 5fb888e666250161ad9812b38718f428a2bac7cc5bfd518c7d9b339906a873e9
[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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1acf1789a64f06510c7d155869837e5af29245bd61d5742e7e570db7f77fd766
[INFO] running `Command { std: "docker" "start" "-a" "1acf1789a64f06510c7d155869837e5af29245bd61d5742e7e570db7f77fd766", kill_on_drop: false }`
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stderr]     Checking routeros_rust v0.0.21 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.68s
[INFO] running `Command { std: "docker" "inspect" "1acf1789a64f06510c7d155869837e5af29245bd61d5742e7e570db7f77fd766", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1acf1789a64f06510c7d155869837e5af29245bd61d5742e7e570db7f77fd766", kill_on_drop: false }`
[INFO] [stdout] 1acf1789a64f06510c7d155869837e5af29245bd61d5742e7e570db7f77fd766
[INFO] checking routeros_rust-0.0.21 against try#3a4bc97f6385a3aa300a4fd689b44350e54fd676 for no-never-type-fallback
[INFO] extracting crate routeros_rust 0.0.21 into /workspace/builds/worker-4-tc2/source
[INFO] validating manifest of crates.io crate routeros_rust 0.0.21 on toolchain 3a4bc97f6385a3aa300a4fd689b44350e54fd676
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate routeros_rust 0.0.21
[INFO] finished tweaking crates.io crate routeros_rust 0.0.21
[INFO] tweaked toml for crates.io crate routeros_rust 0.0.21 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d3b8aee6f82cc49ee02d86d1fff036cc2e6c4f790a006f320d2cb36b8402c82b
[INFO] running `Command { std: "docker" "start" "-a" "d3b8aee6f82cc49ee02d86d1fff036cc2e6c4f790a006f320d2cb36b8402c82b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3b8aee6f82cc49ee02d86d1fff036cc2e6c4f790a006f320d2cb36b8402c82b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3b8aee6f82cc49ee02d86d1fff036cc2e6c4f790a006f320d2cb36b8402c82b", kill_on_drop: false }`
[INFO] [stdout] d3b8aee6f82cc49ee02d86d1fff036cc2e6c4f790a006f320d2cb36b8402c82b
[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" "+3a4bc97f6385a3aa300a4fd689b44350e54fd676" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9601cec0eaf5f6f20f711c68be675b14d9355791e4cee273552acd045c4d10b2
[INFO] running `Command { std: "docker" "start" "-a" "9601cec0eaf5f6f20f711c68be675b14d9355791e4cee273552acd045c4d10b2", kill_on_drop: false }`
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]     Checking rustc-serialize v0.3.25
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]     --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/rustc-serialize-0.3.25/src/json.rs:1387:20
[INFO] [stdout]      |
[INFO] [stdout] 1387 |             _ => { panic!(); }
[INFO] [stdout]      |                    ^^^^^^^^ cannot infer type
[INFO] [stdout]      |
[INFO] [stdout]      = note: this error originates in the macro `$crate::panic::panic_2015` which comes from the expansion of the macro `panic` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rustc-serialize` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "9601cec0eaf5f6f20f711c68be675b14d9355791e4cee273552acd045c4d10b2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9601cec0eaf5f6f20f711c68be675b14d9355791e4cee273552acd045c4d10b2", kill_on_drop: false }`
[INFO] [stdout] 9601cec0eaf5f6f20f711c68be675b14d9355791e4cee273552acd045c4d10b2