[INFO] fetching crate scene-graph 0.1.0...
[INFO] checking scene-graph-0.1.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate scene-graph 0.1.0 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate scene-graph 0.1.0 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 scene-graph 0.1.0
[INFO] finished tweaking crates.io crate scene-graph 0.1.0
[INFO] tweaked toml for crates.io crate scene-graph 0.1.0 written to /workspace/builds/worker-0-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 69 packages
[INFO] [stderr]       Adding bitflags v1.3.2 (latest: v2.5.0)
[INFO] [stderr]       Adding clap v2.34.0 (latest: v4.5.4)
[INFO] [stderr]       Adding criterion v0.3.6 (latest: v0.5.1)
[INFO] [stderr]       Adding criterion-plot v0.4.5 (latest: v0.5.0)
[INFO] [stderr]       Adding fixedbitset v0.4.2 (latest: v0.5.6)
[INFO] [stderr]       Adding half v1.8.3 (latest: v2.4.0)
[INFO] [stderr]       Adding hermit-abi v0.1.19 (latest: v0.3.9)
[INFO] [stderr]       Adding itertools v0.10.5 (latest: v0.12.1)
[INFO] [stderr]       Adding textwrap v0.11.0 (latest: v0.16.1)
[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 thunderdome v0.6.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] d07b0ef273d31074fb3bd6b87577d1341ea42fe693ddca4c499813b3dcbd99c9
[INFO] running `Command { std: "docker" "start" "-a" "d07b0ef273d31074fb3bd6b87577d1341ea42fe693ddca4c499813b3dcbd99c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d07b0ef273d31074fb3bd6b87577d1341ea42fe693ddca4c499813b3dcbd99c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d07b0ef273d31074fb3bd6b87577d1341ea42fe693ddca4c499813b3dcbd99c9", kill_on_drop: false }`
[INFO] [stdout] d07b0ef273d31074fb3bd6b87577d1341ea42fe693ddca4c499813b3dcbd99c9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 493e2551b7f28f4c2815d61c1ae59eaa4b382d3f762504d242bbbe1691fc99d1
[INFO] running `Command { std: "docker" "start" "-a" "493e2551b7f28f4c2815d61c1ae59eaa4b382d3f762504d242bbbe1691fc99d1", kill_on_drop: false }`
[INFO] [stderr]    Compiling thiserror v1.0.58
[INFO] [stderr]     Checking fixedbitset v0.4.2
[INFO] [stderr]     Checking thunderdome v0.6.1
[INFO] [stderr]    Compiling syn v2.0.58
[INFO] [stderr]     Checking petgraph v0.6.4
[INFO] [stderr]    Compiling thiserror-impl v1.0.58
[INFO] [stderr]    Compiling serde_derive v1.0.197
[INFO] [stderr]     Checking scene-graph v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:344:21
[INFO] [stdout]     |
[INFO] [stdout] 344 |                 let mut last_sibling = &mut self.arena[old_last];
[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] [stderr]     Checking criterion v0.3.6
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:344:21
[INFO] [stdout]     |
[INFO] [stdout] 344 |                 let mut last_sibling = &mut self.arena[old_last];
[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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 10.12s
[INFO] running `Command { std: "docker" "inspect" "493e2551b7f28f4c2815d61c1ae59eaa4b382d3f762504d242bbbe1691fc99d1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "493e2551b7f28f4c2815d61c1ae59eaa4b382d3f762504d242bbbe1691fc99d1", kill_on_drop: false }`
[INFO] [stdout] 493e2551b7f28f4c2815d61c1ae59eaa4b382d3f762504d242bbbe1691fc99d1
[INFO] checking scene-graph-0.1.0 against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] extracting crate scene-graph 0.1.0 into /workspace/builds/worker-0-tc2/source
[INFO] validating manifest of crates.io crate scene-graph 0.1.0 on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate scene-graph 0.1.0
[INFO] finished tweaking crates.io crate scene-graph 0.1.0
[INFO] tweaked toml for crates.io crate scene-graph 0.1.0 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3296f57630c9e97e91b2d9ed31012c4515a0ddb243fcbde5c96cb50fa2501990
[INFO] running `Command { std: "docker" "start" "-a" "3296f57630c9e97e91b2d9ed31012c4515a0ddb243fcbde5c96cb50fa2501990", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3296f57630c9e97e91b2d9ed31012c4515a0ddb243fcbde5c96cb50fa2501990", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3296f57630c9e97e91b2d9ed31012c4515a0ddb243fcbde5c96cb50fa2501990", kill_on_drop: false }`
[INFO] [stdout] 3296f57630c9e97e91b2d9ed31012c4515a0ddb243fcbde5c96cb50fa2501990
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 66ce3d35ab0d40f30c2e42f3f4ad2141d8c98e255be14bb0e22ff5801e9822c2
[INFO] running `Command { std: "docker" "start" "-a" "66ce3d35ab0d40f30c2e42f3f4ad2141d8c98e255be14bb0e22ff5801e9822c2", kill_on_drop: false }`
[INFO] [stderr]    Compiling thiserror v1.0.58
[INFO] [stderr]    Compiling syn v2.0.58
[INFO] [stderr]     Checking thunderdome v0.6.1
[INFO] [stderr]     Checking fixedbitset v0.4.2
[INFO] [stderr]     Checking petgraph v0.6.4
[INFO] [stderr]    Compiling thiserror-impl v1.0.58
[INFO] [stderr]    Compiling serde_derive v1.0.197
[INFO] [stderr]     Checking scene-graph v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:344:21
[INFO] [stdout]     |
[INFO] [stdout] 344 |                 let mut last_sibling = &mut self.arena[old_last];
[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] [stderr]     Checking criterion v0.3.6
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:344:21
[INFO] [stdout]     |
[INFO] [stdout] 344 |                 let mut last_sibling = &mut self.arena[old_last];
[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] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 9.12s
[INFO] running `Command { std: "docker" "inspect" "66ce3d35ab0d40f30c2e42f3f4ad2141d8c98e255be14bb0e22ff5801e9822c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66ce3d35ab0d40f30c2e42f3f4ad2141d8c98e255be14bb0e22ff5801e9822c2", kill_on_drop: false }`
[INFO] [stdout] 66ce3d35ab0d40f30c2e42f3f4ad2141d8c98e255be14bb0e22ff5801e9822c2