[INFO] fetching crate serde_wxf 0.0.1...
[INFO] checking serde_wxf-0.0.1 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate serde_wxf 0.0.1 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate serde_wxf 0.0.1 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 serde_wxf 0.0.1
[INFO] finished tweaking crates.io crate serde_wxf 0.0.1
[INFO] tweaked toml for crates.io crate serde_wxf 0.0.1 written to /workspace/builds/worker-2-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 matrixmultiply v0.2.4 (latest: v0.3.8)
[INFO] [stderr]       Adding ndarray v0.13.1 (latest: v0.15.6)
[INFO] [stderr]       Adding num v0.2.1 (latest: v0.4.1)
[INFO] [stderr]       Adding num-bigint v0.2.6 (latest: v0.4.4)
[INFO] [stderr]       Adding num-complex v0.2.4 (latest: v0.4.5)
[INFO] [stderr]       Adding num-rational v0.2.4 (latest: v0.4.1)
[INFO] [stderr]       Adding wolfram_wxf v0.5.0 (latest: v0.7.0)
[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 ndarray v0.13.1
[INFO] [stderr]   Downloaded wolfram_wxf v0.5.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 6b7a7baf01bb78f9df927a192d74d474cb7932b51a7a2b0f37aceb2af0bbf129
[INFO] running `Command { std: "docker" "start" "-a" "6b7a7baf01bb78f9df927a192d74d474cb7932b51a7a2b0f37aceb2af0bbf129", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b7a7baf01bb78f9df927a192d74d474cb7932b51a7a2b0f37aceb2af0bbf129", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b7a7baf01bb78f9df927a192d74d474cb7932b51a7a2b0f37aceb2af0bbf129", kill_on_drop: false }`
[INFO] [stdout] 6b7a7baf01bb78f9df927a192d74d474cb7932b51a7a2b0f37aceb2af0bbf129
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 09c640e175eaf5099f924974b7318d4cee8bfc178e9170ca158e5a73825d06d4
[INFO] running `Command { std: "docker" "start" "-a" "09c640e175eaf5099f924974b7318d4cee8bfc178e9170ca158e5a73825d06d4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.79
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling ndarray v0.13.1
[INFO] [stderr]     Checking miniz_oxide v0.7.2
[INFO] [stderr]     Checking matrixmultiply v0.2.4
[INFO] [stderr]     Checking num-iter v0.1.44
[INFO] [stderr]     Checking flate2 v1.0.28
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.58
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]    Compiling serde_derive v1.0.197
[INFO] [stderr]     Checking wolfram_wxf v0.5.0
[INFO] [stderr]     Checking serde v1.0.197
[INFO] [stderr]     Checking serde_wxf v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:35:12
[INFO] [stdout]    |
[INFO] [stdout] 35 |     fn end(mut self) -> Result<()> {
[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/ser/sequence.rs:52:12
[INFO] [stdout]    |
[INFO] [stdout] 52 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:69:12
[INFO] [stdout]    |
[INFO] [stdout] 69 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:85:12
[INFO] [stdout]    |
[INFO] [stdout] 85 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:35:12
[INFO] [stdout]    |
[INFO] [stdout] 35 |     fn end(mut self) -> Result<()> {
[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/ser/sequence.rs:52:12
[INFO] [stdout]    |
[INFO] [stdout] 52 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:69:12
[INFO] [stdout]    |
[INFO] [stdout] 69 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/ser/sequence.rs:85:12
[INFO] [stdout]    |
[INFO] [stdout] 85 |     fn end(mut self) -> Result<()> {
[INFO] [stdout]    |            ----^^^^
[INFO] [stdout]    |            |
[INFO] [stdout]    |            help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.31s
[INFO] running `Command { std: "docker" "inspect" "09c640e175eaf5099f924974b7318d4cee8bfc178e9170ca158e5a73825d06d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "09c640e175eaf5099f924974b7318d4cee8bfc178e9170ca158e5a73825d06d4", kill_on_drop: false }`
[INFO] [stdout] 09c640e175eaf5099f924974b7318d4cee8bfc178e9170ca158e5a73825d06d4