[INFO] cloning repository https://github.com/carllhw/tokio-hello-world
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/carllhw/tokio-hello-world" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcarllhw%2Ftokio-hello-world", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcarllhw%2Ftokio-hello-world'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f1e7928e2d09fe1311bd31d5b62b28115e4b263f
[INFO] checking carllhw/tokio-hello-world against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcarllhw%2Ftokio-hello-world" "/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/carllhw/tokio-hello-world 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/carllhw/tokio-hello-world
[INFO] finished tweaking git repo https://github.com/carllhw/tokio-hello-world
[INFO] tweaked toml for git repo https://github.com/carllhw/tokio-hello-world written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/carllhw/tokio-hello-world 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 tokio-io v0.1.7
[INFO] [stderr]   Downloaded tokio-udp v0.1.1
[INFO] [stderr]   Downloaded tokio-codec v0.1.0
[INFO] [stderr]   Downloaded bytes v0.4.9
[INFO] [stderr]   Downloaded tokio-fs v0.1.3
[INFO] [stderr]   Downloaded crossbeam-utils v0.3.2
[INFO] [stderr]   Downloaded tokio-tcp v0.1.1
[INFO] [stderr]   Downloaded crossbeam-epoch v0.4.3
[INFO] [stderr]   Downloaded tokio-threadpool v0.1.5
[INFO] [stderr]   Downloaded tokio-timer v0.2.5
[INFO] [stderr]   Downloaded mio v0.6.15
[INFO] [stderr]   Downloaded futures v0.1.23
[INFO] [stderr]   Downloaded tokio v0.1.6
[INFO] [stderr]   Downloaded crossbeam-deque v0.3.1
[INFO] [stderr]   Downloaded slab v0.4.1
[INFO] [stderr]   Downloaded tokio-executor v0.1.3
[INFO] [stderr]   Downloaded byteorder v1.2.4
[INFO] [stderr]   Downloaded tokio-reactor v0.1.3
[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] 11824b39a2635668c0b1aa77e8732f667d144fddd3fae72b3c5a4210a57e916f
[INFO] running `Command { std: "docker" "start" "-a" "11824b39a2635668c0b1aa77e8732f667d144fddd3fae72b3c5a4210a57e916f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "11824b39a2635668c0b1aa77e8732f667d144fddd3fae72b3c5a4210a57e916f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "11824b39a2635668c0b1aa77e8732f667d144fddd3fae72b3c5a4210a57e916f", kill_on_drop: false }`
[INFO] [stdout] 11824b39a2635668c0b1aa77e8732f667d144fddd3fae72b3c5a4210a57e916f
[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] f3f9c8b5d4983e46c5e20ad48c485bd7c2f8540e2e0a0a583813ccc31de44958
[INFO] running `Command { std: "docker" "start" "-a" "f3f9c8b5d4983e46c5e20ad48c485bd7c2f8540e2e0a0a583813ccc31de44958", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.4
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]     Checking futures v0.1.23
[INFO] [stderr]     Checking byteorder v1.2.4
[INFO] [stderr]    Compiling version_check v0.1.4
[INFO] [stderr]     Checking nodrop v0.1.12
[INFO] [stderr]     Checking slab v0.4.1
[INFO] [stderr]     Checking memoffset v0.2.1
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking lazycell v0.6.0
[INFO] [stderr]     Checking log v0.4.3
[INFO] [stderr]     Checking crossbeam-utils v0.3.2
[INFO] [stderr]     Checking arrayvec v0.4.7
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking num_cpus v1.8.0
[INFO] [stderr]     Checking rand v0.4.2
[INFO] [stderr]     Checking crossbeam-epoch v0.4.3
[INFO] [stderr]     Checking bytes v0.4.9
[INFO] [stderr]     Checking mio v0.6.15
[INFO] [stderr]     Checking crossbeam-deque v0.3.1
[INFO] [stderr]     Checking tokio-executor v0.1.3
[INFO] [stderr]     Checking tokio-io v0.1.7
[INFO] [stderr]     Checking tokio-threadpool v0.1.5
[INFO] [stderr]     Checking tokio-timer v0.2.5
[INFO] [stderr]     Checking tokio-reactor v0.1.3
[INFO] [stderr]     Checking tokio-codec v0.1.0
[INFO] [stderr]     Checking tokio-fs v0.1.3
[INFO] [stderr]     Checking tokio-tcp v0.1.1
[INFO] [stderr]     Checking tokio-udp v0.1.1
[INFO] [stderr]     Checking tokio v0.1.6
[INFO] [stderr]     Checking tokio-hello-world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `tokio::io`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use tokio::io;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::io`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use tokio::io;
[INFO] [stdout]   |     ^^^^^^^^^
[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 4.40s
[INFO] running `Command { std: "docker" "inspect" "f3f9c8b5d4983e46c5e20ad48c485bd7c2f8540e2e0a0a583813ccc31de44958", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f3f9c8b5d4983e46c5e20ad48c485bd7c2f8540e2e0a0a583813ccc31de44958", kill_on_drop: false }`
[INFO] [stdout] f3f9c8b5d4983e46c5e20ad48c485bd7c2f8540e2e0a0a583813ccc31de44958
[INFO] checking carllhw/tokio-hello-world against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcarllhw%2Ftokio-hello-world" "/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/carllhw/tokio-hello-world on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/carllhw/tokio-hello-world
[INFO] finished tweaking git repo https://github.com/carllhw/tokio-hello-world
[INFO] tweaked toml for git repo https://github.com/carllhw/tokio-hello-world written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/carllhw/tokio-hello-world 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5b161167b4a9aeae7aa6e8ee26a13fdaa55f80d011c52c092a51032436f5fa5d
[INFO] running `Command { std: "docker" "start" "-a" "5b161167b4a9aeae7aa6e8ee26a13fdaa55f80d011c52c092a51032436f5fa5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5b161167b4a9aeae7aa6e8ee26a13fdaa55f80d011c52c092a51032436f5fa5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5b161167b4a9aeae7aa6e8ee26a13fdaa55f80d011c52c092a51032436f5fa5d", kill_on_drop: false }`
[INFO] [stdout] 5b161167b4a9aeae7aa6e8ee26a13fdaa55f80d011c52c092a51032436f5fa5d
[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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 34137b259b8a9b0d07fd8b6341b595d76338e35c78b2427c8d689e18377e31e3
[INFO] running `Command { std: "docker" "start" "-a" "34137b259b8a9b0d07fd8b6341b595d76338e35c78b2427c8d689e18377e31e3", kill_on_drop: false }`
[INFO] [stderr]     Checking cfg-if v0.1.4
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]     Checking futures v0.1.23
[INFO] [stderr]    Compiling version_check v0.1.4
[INFO] [stderr]     Checking byteorder v1.2.4
[INFO] [stderr]     Checking nodrop v0.1.12
[INFO] [stderr]     Checking slab v0.4.1
[INFO] [stderr]     Checking lazycell v0.6.0
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking memoffset v0.2.1
[INFO] [stderr]     Checking log v0.4.3
[INFO] [stderr]     Checking crossbeam-utils v0.3.2
[INFO] [stderr]     Checking arrayvec v0.4.7
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr]     Checking iovec v0.1.2
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking num_cpus v1.8.0
[INFO] [stderr]     Checking rand v0.4.2
[INFO] [stderr]     Checking bytes v0.4.9
[INFO] [stderr]     Checking crossbeam-epoch v0.4.3
[INFO] [stderr]     Checking mio v0.6.15
[INFO] [stderr]     Checking crossbeam-deque v0.3.1
[INFO] [stderr]     Checking tokio-executor v0.1.3
[INFO] [stderr]     Checking tokio-io v0.1.7
[INFO] [stderr]     Checking tokio-threadpool v0.1.5
[INFO] [stderr]     Checking tokio-timer v0.2.5
[INFO] [stderr]     Checking tokio-reactor v0.1.3
[INFO] [stderr]     Checking tokio-codec v0.1.0
[INFO] [stderr]     Checking tokio-tcp v0.1.1
[INFO] [stderr]     Checking tokio-udp v0.1.1
[INFO] [stderr]     Checking tokio-fs v0.1.3
[INFO] [stderr]     Checking tokio v0.1.6
[INFO] [stderr]     Checking tokio-hello-world v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `tokio::io`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use tokio::io;
[INFO] [stdout]   |     ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `tokio::io`
[INFO] [stdout]  --> src/main.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use tokio::io;
[INFO] [stdout]   |     ^^^^^^^^^
[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 4.56s
[INFO] running `Command { std: "docker" "inspect" "34137b259b8a9b0d07fd8b6341b595d76338e35c78b2427c8d689e18377e31e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34137b259b8a9b0d07fd8b6341b595d76338e35c78b2427c8d689e18377e31e3", kill_on_drop: false }`
[INFO] [stdout] 34137b259b8a9b0d07fd8b6341b595d76338e35c78b2427c8d689e18377e31e3