[INFO] fetching crate envelope 0.8.1...
[INFO] checking envelope-0.8.1 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate envelope 0.8.1 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate envelope 0.8.1 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 envelope 0.8.1
[INFO] finished tweaking crates.io crate envelope 0.8.1
[INFO] tweaked toml for crates.io crate envelope 0.8.1 written to /workspace/builds/worker-4-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 24 packages
[INFO] [stderr]       Adding interpolation v0.1.0 (latest: v0.3.0)
[INFO] [stderr]       Adding itoa v0.1.1 (latest: v1.0.11)
[INFO] [stderr]       Adding num v0.1.42 (latest: v0.4.1)
[INFO] [stderr]       Adding num-bigint v0.1.44 (latest: v0.4.4)
[INFO] [stderr]       Adding num-complex v0.1.43 (latest: v0.4.5)
[INFO] [stderr]       Adding num-rational v0.1.42 (latest: v0.4.1)
[INFO] [stderr]       Adding num-traits v0.1.43 (latest: v0.2.18)
[INFO] [stderr]       Adding rand v0.4.6 (latest: v0.8.5)
[INFO] [stderr]       Adding rand_core v0.3.1 (latest: v0.6.4)
[INFO] [stderr]       Adding rand_core v0.4.2 (latest: v0.6.4)
[INFO] [stderr]       Adding rdrand v0.4.0 (latest: v0.8.3)
[INFO] [stderr]       Adding serde v0.7.15 (latest: v1.0.197)
[INFO] [stderr]       Adding serde_json v0.7.4 (latest: v1.0.115)
[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 num-rational v0.1.42
[INFO] [stderr]   Downloaded serde v0.7.15
[INFO] [stderr]   Downloaded num-bigint v0.1.44
[INFO] [stderr]   Downloaded interpolation v0.1.0
[INFO] [stderr]   Downloaded num-complex v0.1.43
[INFO] [stderr]   Downloaded num v0.1.42
[INFO] [stderr]   Downloaded itoa v0.1.1
[INFO] [stderr]   Downloaded serde_json v0.7.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] be220ecba3b621130606b9bb85e76fa3257aca23c03fcf56865f6af2ada58807
[INFO] running `Command { std: "docker" "start" "-a" "be220ecba3b621130606b9bb85e76fa3257aca23c03fcf56865f6af2ada58807", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "be220ecba3b621130606b9bb85e76fa3257aca23c03fcf56865f6af2ada58807", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "be220ecba3b621130606b9bb85e76fa3257aca23c03fcf56865f6af2ada58807", kill_on_drop: false }`
[INFO] [stdout] be220ecba3b621130606b9bb85e76fa3257aca23c03fcf56865f6af2ada58807
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 232f178390c2f9ca09aa19737359bbc3f0a8307303f34f5088165a9a990c96aa
[INFO] running `Command { std: "docker" "start" "-a" "232f178390c2f9ca09aa19737359bbc3f0a8307303f34f5088165a9a990c96aa", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.25
[INFO] [stderr]     Checking interpolation v0.1.0
[INFO] [stderr]     Checking num-integer v0.1.46
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking num-iter v0.1.44
[INFO] [stderr]     Checking num-bigint v0.1.44
[INFO] [stderr]     Checking num-complex v0.1.43
[INFO] [stderr]     Checking num-rational v0.1.42
[INFO] [stderr]     Checking num v0.1.42
[INFO] [stderr]     Checking envelope v0.8.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `std` is imported redundantly
[INFO] [stdout]  --> src/envelope.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std;
[INFO] [stdout]   |     ^^^ the item `std` is already imported by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `std` is imported redundantly
[INFO] [stdout]  --> src/interpolate.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std;
[INFO] [stdout]   |     ^^^ the item `std` is already imported by prelude
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `std` is imported redundantly
[INFO] [stdout]  --> src/envelope.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std;
[INFO] [stdout]   |     ^^^ the item `std` is already imported by prelude
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `std` is imported redundantly
[INFO] [stdout]  --> src/interpolate.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std;
[INFO] [stdout]   |     ^^^ the item `std` is already imported by prelude
[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 2.02s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: num-bigint v0.1.44, num-complex v0.1.43, num-rational v0.1.42
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 2`
[INFO] running `Command { std: "docker" "inspect" "232f178390c2f9ca09aa19737359bbc3f0a8307303f34f5088165a9a990c96aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "232f178390c2f9ca09aa19737359bbc3f0a8307303f34f5088165a9a990c96aa", kill_on_drop: false }`
[INFO] [stdout] 232f178390c2f9ca09aa19737359bbc3f0a8307303f34f5088165a9a990c96aa