[INFO] fetching crate grrs-alec 0.1.0...
[INFO] checking grrs-alec-0.1.0 against try#39e1293fce4b650061e85dda88aa428f726a8444 for pr-88041
[INFO] extracting crate grrs-alec 0.1.0 into /workspace/builds/worker-19/source
[INFO] validating manifest of crates.io crate grrs-alec 0.1.0 on toolchain 39e1293fce4b650061e85dda88aa428f726a8444
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate grrs-alec 0.1.0
[INFO] finished tweaking crates.io crate grrs-alec 0.1.0
[INFO] tweaked toml for crates.io crate grrs-alec 0.1.0 written to /workspace/builds/worker-19/source/Cargo.toml
[INFO] crate crates.io crate grrs-alec 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "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-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d52fa5d91fc40730d754efabffac2cc2fe5dd17194ca9dc555aac5248a2ba897
[INFO] running `Command { std: "docker" "start" "-a" "d52fa5d91fc40730d754efabffac2cc2fe5dd17194ca9dc555aac5248a2ba897", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d52fa5d91fc40730d754efabffac2cc2fe5dd17194ca9dc555aac5248a2ba897", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d52fa5d91fc40730d754efabffac2cc2fe5dd17194ca9dc555aac5248a2ba897", kill_on_drop: false }`
[INFO] [stdout] d52fa5d91fc40730d754efabffac2cc2fe5dd17194ca9dc555aac5248a2ba897
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 687f8992d10e24524c94f434db16ddfefdbee2e9f376db724daead345bf4d8ad
[INFO] running `Command { std: "docker" "start" "-a" "687f8992d10e24524c94f434db16ddfefdbee2e9f376db724daead345bf4d8ad", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling proc-macro2 v1.0.5
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling cc v1.0.45
[INFO] [stderr]    Compiling failure_derive v0.1.6
[INFO] [stderr]     Checking rustc-demangle v0.1.16
[INFO] [stderr]     Checking unicode-width v0.1.6
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling structopt-derive v0.2.18
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]     Checking backtrace v0.3.38
[INFO] [stderr]     Checking structopt v0.2.18
[INFO] [stderr]    Compiling synstructure v0.12.1
[INFO] [stderr]     Checking failure v0.1.6
[INFO] [stderr]     Checking exitfailure v0.5.1
[INFO] [stderr]     Checking grrs-alec v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:28:7
[INFO] [stdout]    |
[INFO] [stdout] 28 |       writeln!(writer, "{}", line);
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:28:7
[INFO] [stdout]    |
[INFO] [stdout] 28 |       writeln!(writer, "{}", line);
[INFO] [stdout]    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: this warning originates in the macro `writeln` (in Nightly builds, run with -Z macro-backtrace for more info)
[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 [unoptimized + debuginfo] target(s) in 15.22s
[INFO] running `Command { std: "docker" "inspect" "687f8992d10e24524c94f434db16ddfefdbee2e9f376db724daead345bf4d8ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "687f8992d10e24524c94f434db16ddfefdbee2e9f376db724daead345bf4d8ad", kill_on_drop: false }`
[INFO] [stdout] 687f8992d10e24524c94f434db16ddfefdbee2e9f376db724daead345bf4d8ad