[INFO] fetching crate metrics-recorder-prometheus 0.2.3...
[INFO] checking metrics-recorder-prometheus-0.2.3 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate metrics-recorder-prometheus 0.2.3 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate metrics-recorder-prometheus 0.2.3 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 metrics-recorder-prometheus 0.2.3
[INFO] finished tweaking crates.io crate metrics-recorder-prometheus 0.2.3
[INFO] tweaked toml for crates.io crate metrics-recorder-prometheus 0.2.3 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 26 packages
[INFO] [stderr]       Adding arrayvec v0.4.12 (latest: v0.7.4)
[INFO] [stderr]       Adding base64 v0.10.1 (latest: v0.22.0)
[INFO] [stderr]       Adding cfg-if v0.1.10 (latest: v1.0.0)
[INFO] [stderr]       Adding crossbeam-channel v0.3.9 (latest: v0.5.12)
[INFO] [stderr]       Adding crossbeam-epoch v0.7.2 (latest: v0.9.18)
[INFO] [stderr]       Adding crossbeam-utils v0.6.6 (latest: v0.8.19)
[INFO] [stderr]       Adding futures v0.1.31 (latest: v0.3.30)
[INFO] [stderr]       Adding hdrhistogram v6.3.4 (latest: v7.5.4)
[INFO] [stderr]       Adding memoffset v0.5.6 (latest: v0.9.1)
[INFO] [stderr]       Adding metrics-core v0.4.0 (latest: v0.5.2)
[INFO] [stderr]       Adding metrics-util v0.2.1 (latest: v0.16.3)
[INFO] [stderr]       Adding nom v4.2.3 (latest: v7.1.3)
[INFO] [stderr]       Adding version_check v0.1.5 (latest: v0.9.4)
[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 arrayvec v0.4.12
[INFO] [stderr]   Downloaded metrics-core v0.4.0
[INFO] [stderr]   Downloaded hdrhistogram v6.3.4
[INFO] [stderr]   Downloaded metrics-util v0.2.1
[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] 97634329eff0929e4a728160beb52f62929429b7b55ed78cf6d22538319c1ace
[INFO] running `Command { std: "docker" "start" "-a" "97634329eff0929e4a728160beb52f62929429b7b55ed78cf6d22538319c1ace", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "97634329eff0929e4a728160beb52f62929429b7b55ed78cf6d22538319c1ace", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97634329eff0929e4a728160beb52f62929429b7b55ed78cf6d22538319c1ace", kill_on_drop: false }`
[INFO] [stdout] 97634329eff0929e4a728160beb52f62929429b7b55ed78cf6d22538319c1ace
[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] a271ed479dac8bf0e70fff040089d041765972c9f9249e4169ab6eae821a7c6d
[INFO] running `Command { std: "docker" "start" "-a" "a271ed479dac8bf0e70fff040089d041765972c9f9249e4169ab6eae821a7c6d", kill_on_drop: false }`
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]     Checking memchr v2.7.2
[INFO] [stderr]     Checking metrics-core v0.4.0
[INFO] [stderr]     Checking crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking metrics-util v0.2.1
[INFO] [stderr]     Checking hdrhistogram v6.3.4
[INFO] [stderr]     Checking metrics-recorder-prometheus v0.2.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:64:13
[INFO] [stdout]    |
[INFO] [stdout] 64 |         let mut parts = self.histograms.entry(key.into().to_string()).or_insert_with(|| {
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:64:13
[INFO] [stdout]    |
[INFO] [stdout] 64 |         let mut parts = self.histograms.entry(key.into().to_string()).or_insert_with(|| {
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` 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 4.26s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: hdrhistogram v6.3.4, nom v4.2.3
[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" "a271ed479dac8bf0e70fff040089d041765972c9f9249e4169ab6eae821a7c6d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a271ed479dac8bf0e70fff040089d041765972c9f9249e4169ab6eae821a7c6d", kill_on_drop: false }`
[INFO] [stdout] a271ed479dac8bf0e70fff040089d041765972c9f9249e4169ab6eae821a7c6d