[INFO] fetching crate preftool 0.2.0...
[INFO] checking preftool-0.2.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate preftool 0.2.0 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate preftool 0.2.0 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 preftool 0.2.0
[INFO] finished tweaking crates.io crate preftool 0.2.0
[INFO] tweaked toml for crates.io crate preftool 0.2.0 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 31 packages
[INFO] [stderr]       Adding crossbeam v0.2.12 (latest: v0.8.4)
[INFO] [stderr]       Adding log v0.3.9 (latest: v0.4.21)
[INFO] [stderr]       Adding object v0.32.2 (latest: v0.34.0)
[INFO] [stderr]       Adding slog-stdlog v3.0.5 (latest: v4.1.1)
[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 caseless v0.2.1
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0d9e3d0d05cf90a7a8dfa4c7223aaec6f64ec5d6a166b2f752ea6c1219439ebd
[INFO] running `Command { std: "docker" "start" "-a" "0d9e3d0d05cf90a7a8dfa4c7223aaec6f64ec5d6a166b2f752ea6c1219439ebd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0d9e3d0d05cf90a7a8dfa4c7223aaec6f64ec5d6a166b2f752ea6c1219439ebd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d9e3d0d05cf90a7a8dfa4c7223aaec6f64ec5d6a166b2f752ea6c1219439ebd", kill_on_drop: false }`
[INFO] [stdout] 0d9e3d0d05cf90a7a8dfa4c7223aaec6f64ec5d6a166b2f752ea6c1219439ebd
[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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 781e4f974b4be25267a29fa6cae3bd0fcaf8c50427611e1c803d9b58b0a54aa7
[INFO] running `Command { std: "docker" "start" "-a" "781e4f974b4be25267a29fa6cae3bd0fcaf8c50427611e1c803d9b58b0a54aa7", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.7.2
[INFO] [stderr]    Compiling regex-syntax v0.8.3
[INFO] [stderr]    Compiling libc v0.2.153
[INFO] [stderr]    Compiling slog v2.7.0
[INFO] [stderr]    Compiling cc v1.0.90
[INFO] [stderr]     Checking tinyvec_macros v0.1.1
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]     Checking gimli v0.28.1
[INFO] [stderr]    Compiling version_check v0.9.4
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling aho-corasick v1.1.3
[INFO] [stderr]     Checking object v0.32.2
[INFO] [stderr]     Checking miniz_oxide v0.7.2
[INFO] [stderr]     Checking tinyvec v1.6.0
[INFO] [stderr]     Checking rustc-demangle v0.1.23
[INFO] [stderr]     Checking arc-swap v1.7.1
[INFO] [stderr]     Checking log v0.4.21
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking slog-scope v4.4.0
[INFO] [stderr]    Compiling cargo-husky v1.5.0
[INFO] [stderr]     Checking crossbeam v0.2.12
[INFO] [stderr]    Compiling backtrace v0.3.71
[INFO] [stderr]     Checking unicode-normalization v0.1.23
[INFO] [stderr]     Checking slog-stdlog v3.0.5
[INFO] [stderr]     Checking addr2line v0.21.0
[INFO] [stderr]    Compiling regex-automata v0.4.6
[INFO] [stderr]    Compiling regex v1.10.4
[INFO] [stderr]    Compiling caseless v0.2.1
[INFO] [stderr]     Checking preftool v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `Deref` is imported redundantly
[INFO] [stdout]  --> src/config.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use crate::*;
[INFO] [stdout]   |     -------- the item `Deref` is already imported here
[INFO] [stdout] 2 | use std::fmt;
[INFO] [stdout] 3 | use std::ops::Deref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Deref` is imported redundantly
[INFO] [stdout]  --> src/config.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use crate::*;
[INFO] [stdout]   |     -------- the item `Deref` is already imported here
[INFO] [stdout] 2 | use std::fmt;
[INFO] [stdout] 3 | use std::ops::Deref;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/bind.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 144 |     let _ = std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]    --> src/bind.rs:144:5
[INFO] [stdout]     |
[INFO] [stdout] 144 |     std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 144 |     let _ = std::mem::replace(value, proxy.into());
[INFO] [stdout]     |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 22.69s
[INFO] running `Command { std: "docker" "inspect" "781e4f974b4be25267a29fa6cae3bd0fcaf8c50427611e1c803d9b58b0a54aa7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "781e4f974b4be25267a29fa6cae3bd0fcaf8c50427611e1c803d9b58b0a54aa7", kill_on_drop: false }`
[INFO] [stdout] 781e4f974b4be25267a29fa6cae3bd0fcaf8c50427611e1c803d9b58b0a54aa7