[INFO] fetching crate tower 0.4.13...
[INFO] checking tower-0.4.13 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate tower 0.4.13 into /workspace/builds/worker-1-tc1/source
[INFO] validating manifest of crates.io crate tower 0.4.13 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 crates.io crate tower 0.4.13
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate tower 0.4.13
[INFO] tweaked toml for crates.io crate tower 0.4.13 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] crate crates.io crate tower 0.4.13 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tower-test v0.4.0
[INFO] [stderr]   Downloaded tokio-test v0.4.2
[INFO] [stderr]   Downloaded indexmap v1.9.0
[INFO] [stderr]   Downloaded tracing-core v0.1.27
[INFO] [stderr]   Downloaded hdrhistogram v7.5.0
[INFO] [stderr]   Downloaded tracing-subscriber v0.3.11
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 6ea5fa632b2c427557bc46b71d7af899f2c6d48212635b735d5e00321191e2f3
[INFO] running `Command { std: "docker" "start" "-a" "6ea5fa632b2c427557bc46b71d7af899f2c6d48212635b735d5e00321191e2f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6ea5fa632b2c427557bc46b71d7af899f2c6d48212635b735d5e00321191e2f3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6ea5fa632b2c427557bc46b71d7af899f2c6d48212635b735d5e00321191e2f3", kill_on_drop: false }`
[INFO] [stdout] 6ea5fa632b2c427557bc46b71d7af899f2c6d48212635b735d5e00321191e2f3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 815e5a5f4d3f13f645e274a5721a77f351ea43ed6e242fefe56e73975b2d40d7
[INFO] running `Command { std: "docker" "start" "-a" "815e5a5f4d3f13f645e274a5721a77f351ea43ed6e242fefe56e73975b2d40d7", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-ident v1.0.1
[INFO] [stderr]    Compiling syn v1.0.96
[INFO] [stderr]    Compiling futures-core v0.3.21
[INFO] [stderr]     Checking pin-project-lite v0.2.9
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]    Compiling futures-task v0.3.21
[INFO] [stderr]     Checking futures-sink v0.3.21
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]     Checking slab v0.4.6
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking futures-io v0.3.21
[INFO] [stderr]     Checking tracing-core v0.1.27
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]     Checking tower-layer v0.3.1
[INFO] [stderr]     Checking sharded-slab v0.1.4
[INFO] [stderr]     Checking thread_local v1.1.4
[INFO] [stderr]     Checking http v0.2.8
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking tracing v0.1.35
[INFO] [stderr]     Checking tracing-subscriber v0.3.11
[INFO] [stderr]     Checking tower v0.4.13 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait `Sealed` is never used
[INFO] [stdout]    --> src/lib.rs:238:15
[INFO] [stdout]     |
[INFO] [stdout] 238 |     pub trait Sealed<T> {}
[INFO] [stdout]     |               ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking hdrhistogram v7.5.0
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling tokio-macros v1.8.0
[INFO] [stderr]    Compiling async-stream-impl v0.3.3
[INFO] [stderr]    Compiling pin-project-internal v1.0.10
[INFO] [stderr]     Checking async-stream v0.3.3
[INFO] [stderr]     Checking tokio v1.19.2
[INFO] [stderr]     Checking pin-project v1.0.10
[INFO] [stderr]     Checking tokio-stream v0.1.9
[INFO] [stderr]     Checking tokio-test v0.4.2
[INFO] [stderr]     Checking futures-executor v0.3.21
[INFO] [stderr]     Checking tower-test v0.4.0
[INFO] [stderr]     Checking futures v0.3.21
[INFO] [stdout] warning: trait `Sealed` is never used
[INFO] [stdout]    --> src/lib.rs:238:15
[INFO] [stdout]     |
[INFO] [stdout] 238 |     pub trait Sealed<T> {}
[INFO] [stdout]     |               ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.05s
[INFO] running `Command { std: "docker" "inspect" "815e5a5f4d3f13f645e274a5721a77f351ea43ed6e242fefe56e73975b2d40d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "815e5a5f4d3f13f645e274a5721a77f351ea43ed6e242fefe56e73975b2d40d7", kill_on_drop: false }`
[INFO] [stdout] 815e5a5f4d3f13f645e274a5721a77f351ea43ed6e242fefe56e73975b2d40d7