[INFO] cloning repository https://github.com/bww/multiread
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/bww/multiread" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbww%2Fmultiread", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbww%2Fmultiread'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 874bf4de80fc2890db382584d2db8e66616ba17b
[INFO] checking bww/multiread against master#22572d0994593197593e2a1b7b18d720a9a349a7 for pr-126452-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbww%2Fmultiread" "/workspace/builds/worker-7-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/bww/multiread on toolchain 22572d0994593197593e2a1b7b18d720a9a349a7
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/bww/multiread
[INFO] finished tweaking git repo https://github.com/bww/multiread
[INFO] tweaked toml for git repo https://github.com/bww/multiread written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/bww/multiread 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" "+22572d0994593197593e2a1b7b18d720a9a349a7" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio v1.9.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fc4d22b197cbe6471bd009d05e709e8474c2eeeea98b51fab1fc3e6bfdcf5016
[INFO] running `Command { std: "docker" "start" "-a" "fc4d22b197cbe6471bd009d05e709e8474c2eeeea98b51fab1fc3e6bfdcf5016", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fc4d22b197cbe6471bd009d05e709e8474c2eeeea98b51fab1fc3e6bfdcf5016", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc4d22b197cbe6471bd009d05e709e8474c2eeeea98b51fab1fc3e6bfdcf5016", kill_on_drop: false }`
[INFO] [stdout] fc4d22b197cbe6471bd009d05e709e8474c2eeeea98b51fab1fc3e6bfdcf5016
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+22572d0994593197593e2a1b7b18d720a9a349a7" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2500551f478db34476927946739ee47b45098e989bf113cbd9a4cf0901a50b6c
[INFO] running `Command { std: "docker" "start" "-a" "2500551f478db34476927946739ee47b45098e989bf113cbd9a4cf0901a50b6c", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling futures-core v0.3.16
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling futures-macro v0.3.16
[INFO] [stderr]    Compiling futures-channel v0.3.16
[INFO] [stderr]    Compiling futures-task v0.3.16
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling futures-util v0.3.16
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking futures-sink v0.3.16
[INFO] [stderr]     Checking pin-project-lite v0.2.7
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]     Checking futures-io v0.3.16
[INFO] [stderr]     Checking slab v0.4.3
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]    Compiling tokio v1.9.0
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]     Checking once_cell v1.8.0
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking mio v0.7.13
[INFO] [stderr]     Checking dashmap v4.0.2
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]    Compiling tokio-macros v1.3.0
[INFO] [stderr]     Checking futures-executor v0.3.16
[INFO] [stderr]     Checking futures v0.3.16
[INFO] [stderr]     Checking multiread v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/client.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 | /         block_on(async {
[INFO] [stdout] 32 | |           return join!(f1, f2);
[INFO] [stdout] 33 | |         });
[INFO] [stdout]    | |__________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/client.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 | /         block_on(async {
[INFO] [stdout] 32 | |           return join!(f1, f2);
[INFO] [stdout] 33 | |         });
[INFO] [stdout]    | |__________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` 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 14.08s
[INFO] running `Command { std: "docker" "inspect" "2500551f478db34476927946739ee47b45098e989bf113cbd9a4cf0901a50b6c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2500551f478db34476927946739ee47b45098e989bf113cbd9a4cf0901a50b6c", kill_on_drop: false }`
[INFO] [stdout] 2500551f478db34476927946739ee47b45098e989bf113cbd9a4cf0901a50b6c
[INFO] checking bww/multiread against try#6289438dbad80b1a0029c66dd3f6abf57c2c51be for pr-126452-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbww%2Fmultiread" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/bww/multiread on toolchain 6289438dbad80b1a0029c66dd3f6abf57c2c51be
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+6289438dbad80b1a0029c66dd3f6abf57c2c51be" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/bww/multiread
[INFO] finished tweaking git repo https://github.com/bww/multiread
[INFO] tweaked toml for git repo https://github.com/bww/multiread written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/bww/multiread 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" "+6289438dbad80b1a0029c66dd3f6abf57c2c51be" "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-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+6289438dbad80b1a0029c66dd3f6abf57c2c51be" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ea67fb269920dfc03a283d8c3e4898286abeb44920e15a6228ccd03259a5c4a1
[INFO] running `Command { std: "docker" "start" "-a" "ea67fb269920dfc03a283d8c3e4898286abeb44920e15a6228ccd03259a5c4a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ea67fb269920dfc03a283d8c3e4898286abeb44920e15a6228ccd03259a5c4a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea67fb269920dfc03a283d8c3e4898286abeb44920e15a6228ccd03259a5c4a1", kill_on_drop: false }`
[INFO] [stdout] ea67fb269920dfc03a283d8c3e4898286abeb44920e15a6228ccd03259a5c4a1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+6289438dbad80b1a0029c66dd3f6abf57c2c51be" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 03835584e912859b14a18b384fe2413d6c058b01f7c5dd8dfebc6d890bc2a8c2
[INFO] running `Command { std: "docker" "start" "-a" "03835584e912859b14a18b384fe2413d6c058b01f7c5dd8dfebc6d890bc2a8c2", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling futures-core v0.3.16
[INFO] [stderr]    Compiling futures-macro v0.3.16
[INFO] [stderr]    Compiling futures-task v0.3.16
[INFO] [stderr]    Compiling futures-channel v0.3.16
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]    Compiling futures-util v0.3.16
[INFO] [stderr]     Checking futures-sink v0.3.16
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking pin-project-lite v0.2.7
[INFO] [stderr]     Checking instant v0.1.10
[INFO] [stderr]     Checking slab v0.4.3
[INFO] [stderr]     Checking futures-io v0.3.16
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking smallvec v1.6.1
[INFO] [stderr]    Compiling tokio v1.9.0
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]     Checking bytes v1.0.1
[INFO] [stderr]     Checking once_cell v1.8.0
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking parking_lot_core v0.8.3
[INFO] [stderr]     Checking mio v0.7.13
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking dashmap v4.0.2
[INFO] [stderr]     Checking parking_lot v0.11.1
[INFO] [stderr]    Compiling tokio-macros v1.3.0
[INFO] [stderr]     Checking futures-executor v0.3.16
[INFO] [stderr]     Checking futures v0.3.16
[INFO] [stderr]     Checking multiread v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/client.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 | /         block_on(async {
[INFO] [stdout] 32 | |           return join!(f1, f2);
[INFO] [stdout] 33 | |         });
[INFO] [stdout]    | |__________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` in tuple element 1 that must be used
[INFO] [stdout]   --> src/client.rs:31:9
[INFO] [stdout]    |
[INFO] [stdout] 31 | /         block_on(async {
[INFO] [stdout] 32 | |           return join!(f1, f2);
[INFO] [stdout] 33 | |         });
[INFO] [stdout]    | |__________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` 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 12.13s
[INFO] running `Command { std: "docker" "inspect" "03835584e912859b14a18b384fe2413d6c058b01f7c5dd8dfebc6d890bc2a8c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03835584e912859b14a18b384fe2413d6c058b01f7c5dd8dfebc6d890bc2a8c2", kill_on_drop: false }`
[INFO] [stdout] 03835584e912859b14a18b384fe2413d6c058b01f7c5dd8dfebc6d890bc2a8c2