[INFO] fetching crate cargo-referendum 0.1.1...
[INFO] checking cargo-referendum-0.1.1 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate cargo-referendum 0.1.1 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate cargo-referendum 0.1.1 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 cargo-referendum 0.1.1
[INFO] finished tweaking crates.io crate cargo-referendum 0.1.1
[INFO] tweaked toml for crates.io crate cargo-referendum 0.1.1 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate crates.io crate cargo-referendum 0.1.1 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]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded string-builder v0.2.0
[INFO] [stderr]   Downloaded memchr v2.4.0
[INFO] [stderr]   Downloaded xoroshiro128 v0.3.0
[INFO] [stderr]   Downloaded thiserror v1.0.25
[INFO] [stderr]   Downloaded fasthash v0.4.0
[INFO] [stderr]   Downloaded thiserror-impl v1.0.25
[INFO] [stderr]   Downloaded syn v1.0.73
[INFO] [stderr]   Downloaded fasthash-sys v0.3.2
[INFO] [stderr]   Downloaded libc v0.2.97
[INFO] [stderr]   Downloaded seahash v3.0.7
[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] 00a798ed87a84448a081ce0e36728ecb5df6a10a83c1094c9376702def876ac6
[INFO] running `Command { std: "docker" "start" "-a" "00a798ed87a84448a081ce0e36728ecb5df6a10a83c1094c9376702def876ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "00a798ed87a84448a081ce0e36728ecb5df6a10a83c1094c9376702def876ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "00a798ed87a84448a081ce0e36728ecb5df6a10a83c1094c9376702def876ac6", kill_on_drop: false }`
[INFO] [stdout] 00a798ed87a84448a081ce0e36728ecb5df6a10a83c1094c9376702def876ac6
[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] 99e1aad62bf364bfec28193a9e85ead29ccdf504b580916f57eaba8654ddd2cf
[INFO] running `Command { std: "docker" "start" "-a" "99e1aad62bf364bfec28193a9e85ead29ccdf504b580916f57eaba8654ddd2cf", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.97
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]     Checking seahash v3.0.7
[INFO] [stderr]     Checking vec_map v0.8.2
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking string-builder v0.2.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling fasthash-sys v0.3.2
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking xoroshiro128 v0.3.0
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]    Compiling thiserror-impl v1.0.25
[INFO] [stderr]     Checking thiserror v1.0.25
[INFO] [stderr]     Checking fasthash v0.4.0
[INFO] [stderr]     Checking cargo-referendum v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: value assigned to `toolkits` is never read
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let mut toolkits: Vec<_> = Vec::new();
[INFO] [stdout]    |             ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `old_toolkits`
[INFO] [stdout]   --> src/main.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let old_toolkits = vec![
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_old_toolkits`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: value assigned to `toolkits` is never read
[INFO] [stdout]   --> src/main.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let mut toolkits: Vec<_> = Vec::new();
[INFO] [stdout]    |             ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: maybe it is overwritten before being read?
[INFO] [stdout]    = note: `#[warn(unused_assignments)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `old_toolkits`
[INFO] [stdout]   --> src/main.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let old_toolkits = vec![
[INFO] [stdout]    |         ^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_old_toolkits`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.44s
[INFO] running `Command { std: "docker" "inspect" "99e1aad62bf364bfec28193a9e85ead29ccdf504b580916f57eaba8654ddd2cf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "99e1aad62bf364bfec28193a9e85ead29ccdf504b580916f57eaba8654ddd2cf", kill_on_drop: false }`
[INFO] [stdout] 99e1aad62bf364bfec28193a9e85ead29ccdf504b580916f57eaba8654ddd2cf