[INFO] cloning repository https://github.com/huangjj27/guess_wasi
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/huangjj27/guess_wasi" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhuangjj27%2Fguess_wasi", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhuangjj27%2Fguess_wasi'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] eaa161173d7d3180e664a02c2a87ddd93abce037
[INFO] checking huangjj27/guess_wasi against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhuangjj27%2Fguess_wasi" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/huangjj27/guess_wasi 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 git repo https://github.com/huangjj27/guess_wasi
[INFO] finished tweaking git repo https://github.com/huangjj27/guess_wasi
[INFO] tweaked toml for git repo https://github.com/huangjj27/guess_wasi written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/huangjj27/guess_wasi 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 structopt-derive v0.2.16
[INFO] [stderr]   Downloaded syn v0.15.36
[INFO] [stderr]   Downloaded rand_chacha v0.2.0
[INFO] [stderr]   Downloaded rand_core v0.5.0
[INFO] [stderr]   Downloaded structopt v0.2.16
[INFO] [stderr]   Downloaded rand v0.7.0-pre.1
[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] be3de0401d83d6a899683e604dc3ab75b50ca70afefcc697b965e64e80d55638
[INFO] running `Command { std: "docker" "start" "-a" "be3de0401d83d6a899683e604dc3ab75b50ca70afefcc697b965e64e80d55638", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "be3de0401d83d6a899683e604dc3ab75b50ca70afefcc697b965e64e80d55638", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "be3de0401d83d6a899683e604dc3ab75b50ca70afefcc697b965e64e80d55638", kill_on_drop: false }`
[INFO] [stdout] be3de0401d83d6a899683e604dc3ab75b50ca70afefcc697b965e64e80d55638
[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] e8802f1ab526ae636d707be1b8656b37ff6c655599b5febeb26919d85ddbb385
[INFO] running `Command { std: "docker" "start" "-a" "e8802f1ab526ae636d707be1b8656b37ff6c655599b5febeb26919d85ddbb385", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling bitflags v1.1.0
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]     Checking ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking regex-syntax v0.6.7
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]    Compiling rand_chacha v0.2.0
[INFO] [stderr]    Compiling rand v0.7.0-pre.1
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking getrandom v0.1.3
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking rand_core v0.5.0
[INFO] [stderr]    Compiling structopt-derive v0.2.16
[INFO] [stderr]     Checking structopt v0.2.16
[INFO] [stderr]     Checking env_logger v0.6.1
[INFO] [stderr]     Checking guess_wasi v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/main.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rand::{self, Rng};  // currently only support wasm32-wasi target in nightly
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/main.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rand::{self, Rng};  // currently only support wasm32-wasi target in nightly
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` 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 6.75s
[INFO] running `Command { std: "docker" "inspect" "e8802f1ab526ae636d707be1b8656b37ff6c655599b5febeb26919d85ddbb385", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8802f1ab526ae636d707be1b8656b37ff6c655599b5febeb26919d85ddbb385", kill_on_drop: false }`
[INFO] [stdout] e8802f1ab526ae636d707be1b8656b37ff6c655599b5febeb26919d85ddbb385
[INFO] checking huangjj27/guess_wasi against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhuangjj27%2Fguess_wasi" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/huangjj27/guess_wasi 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 git repo https://github.com/huangjj27/guess_wasi
[INFO] finished tweaking git repo https://github.com/huangjj27/guess_wasi
[INFO] tweaked toml for git repo https://github.com/huangjj27/guess_wasi written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/huangjj27/guess_wasi 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] fadd7606afa612c79c1948dbf12e8f8f4a66db9da2238413e78e6788c0d02a0a
[INFO] running `Command { std: "docker" "start" "-a" "fadd7606afa612c79c1948dbf12e8f8f4a66db9da2238413e78e6788c0d02a0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fadd7606afa612c79c1948dbf12e8f8f4a66db9da2238413e78e6788c0d02a0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fadd7606afa612c79c1948dbf12e8f8f4a66db9da2238413e78e6788c0d02a0a", kill_on_drop: false }`
[INFO] [stdout] fadd7606afa612c79c1948dbf12e8f8f4a66db9da2238413e78e6788c0d02a0a
[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] 658ab328469b7686c8d2090db7245258ccb3371fe7002d2eaf3ab407d97eb00b
[INFO] running `Command { std: "docker" "start" "-a" "658ab328469b7686c8d2090db7245258ccb3371fe7002d2eaf3ab407d97eb00b", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]    Compiling bitflags v1.1.0
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.5
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking regex-syntax v0.6.7
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]    Compiling rand_chacha v0.2.0
[INFO] [stderr]    Compiling rand v0.7.0-pre.1
[INFO] [stderr]     Checking c2-chacha v0.2.2
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking getrandom v0.1.3
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking rand_core v0.5.0
[INFO] [stderr]    Compiling structopt-derive v0.2.16
[INFO] [stderr]     Checking env_logger v0.6.1
[INFO] [stderr]     Checking structopt v0.2.16
[INFO] [stderr]     Checking guess_wasi v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/main.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rand::{self, Rng};  // currently only support wasm32-wasi target in nightly
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]  --> src/main.rs:3:12
[INFO] [stdout]   |
[INFO] [stdout] 3 | use rand::{self, Rng};  // currently only support wasm32-wasi target in nightly
[INFO] [stdout]   |            ^^^^ the item `rand` is already defined by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` 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 7.54s
[INFO] running `Command { std: "docker" "inspect" "658ab328469b7686c8d2090db7245258ccb3371fe7002d2eaf3ab407d97eb00b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "658ab328469b7686c8d2090db7245258ccb3371fe7002d2eaf3ab407d97eb00b", kill_on_drop: false }`
[INFO] [stdout] 658ab328469b7686c8d2090db7245258ccb3371fe7002d2eaf3ab407d97eb00b