[INFO] cloning repository https://github.com/hniemeyer/rust_async_example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hniemeyer/rust_async_example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhniemeyer%2Frust_async_example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhniemeyer%2Frust_async_example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3d2997078a81f9ed6b204c4a97f978f9577bbaf4
[INFO] checking hniemeyer/rust_async_example against master#8424f8e8cdf07010967a57584fd647b30e930d4d for pr-120095
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhniemeyer%2Frust_async_example" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hniemeyer/rust_async_example on toolchain 8424f8e8cdf07010967a57584fd647b30e930d4d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8424f8e8cdf07010967a57584fd647b30e930d4d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/hniemeyer/rust_async_example
[INFO] finished tweaking git repo https://github.com/hniemeyer/rust_async_example
[INFO] tweaked toml for git repo https://github.com/hniemeyer/rust_async_example written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/hniemeyer/rust_async_example 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" "+8424f8e8cdf07010967a57584fd647b30e930d4d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking hniemeyer/rust_async_example against try#047472f299946caf090d1b5608ae4bd9f0416256+rustflags=-Ddereferencing_mut_binding for pr-120095
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhniemeyer%2Frust_async_example" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hniemeyer/rust_async_example on toolchain 047472f299946caf090d1b5608ae4bd9f0416256
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+047472f299946caf090d1b5608ae4bd9f0416256" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/hniemeyer/rust_async_example
[INFO] finished tweaking git repo https://github.com/hniemeyer/rust_async_example
[INFO] tweaked toml for git repo https://github.com/hniemeyer/rust_async_example written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/hniemeyer/rust_async_example 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" "+047472f299946caf090d1b5608ae4bd9f0416256" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+047472f299946caf090d1b5608ae4bd9f0416256" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d3b78a0bd6265af57b73c102d4349656f1b82972a4e97bf08ae5c60aac50cc58
[INFO] running `Command { std: "docker" "start" "-a" "d3b78a0bd6265af57b73c102d4349656f1b82972a4e97bf08ae5c60aac50cc58", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d3b78a0bd6265af57b73c102d4349656f1b82972a4e97bf08ae5c60aac50cc58", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3b78a0bd6265af57b73c102d4349656f1b82972a4e97bf08ae5c60aac50cc58", kill_on_drop: false }`
[INFO] [stdout] d3b78a0bd6265af57b73c102d4349656f1b82972a4e97bf08ae5c60aac50cc58
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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 -Ddereferencing_mut_binding" "-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" "+047472f299946caf090d1b5608ae4bd9f0416256" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8b5d95887657545047baeba1eb86d8eb6cbdb40b681a0f2bc23c98c6a8853ccf
[INFO] running `Command { std: "docker" "start" "-a" "8b5d95887657545047baeba1eb86d8eb6cbdb40b681a0f2bc23c98c6a8853ccf", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]     Checking smallvec v1.4.2
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking arc-swap v0.4.7
[INFO] [stderr]     Checking ppv-lite86 v0.2.9
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]     Checking pin-project-lite v0.2.4
[INFO] [stderr]     Checking once_cell v1.5.2
[INFO] [stderr]     Checking instant v0.1.8
[INFO] [stderr]     Checking lock_api v0.4.1
[INFO] [stderr]    Compiling tokio v1.1.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking parking_lot_core v0.8.0
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking signal-hook-registry v1.2.1
[INFO] [stderr]     Checking mio v0.7.7
[INFO] [stderr]     Checking rand_core v0.6.1
[INFO] [stderr]     Checking parking_lot v0.11.0
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]    Compiling tokio-macros v1.0.0
[INFO] [stderr]     Checking trytokio v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.43s
[INFO] running `Command { std: "docker" "inspect" "8b5d95887657545047baeba1eb86d8eb6cbdb40b681a0f2bc23c98c6a8853ccf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8b5d95887657545047baeba1eb86d8eb6cbdb40b681a0f2bc23c98c6a8853ccf", kill_on_drop: false }`
[INFO] [stdout] 8b5d95887657545047baeba1eb86d8eb6cbdb40b681a0f2bc23c98c6a8853ccf