[INFO] fetching crate flem-serial-rs 0.3.0...
[INFO] checking flem-serial-rs-0.3.0 against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] extracting crate flem-serial-rs 0.3.0 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate flem-serial-rs 0.3.0 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 flem-serial-rs 0.3.0
[INFO] finished tweaking crates.io crate flem-serial-rs 0.3.0
[INFO] tweaked toml for crates.io crate flem-serial-rs 0.3.0 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] crate crates.io crate flem-serial-rs 0.3.0 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 mach2 v0.4.1
[INFO] [stderr]   Downloaded IOKit-sys v0.1.5
[INFO] [stderr]   Downloaded bitflags v2.0.2
[INFO] [stderr]   Downloaded flem v0.6.2
[INFO] [stderr]   Downloaded CoreFoundation-sys v0.1.4
[INFO] [stderr]   Downloaded mach v0.1.2
[INFO] [stderr]   Downloaded serialport v4.2.2
[INFO] [stderr]   Downloaded libudev v0.3.0
[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] 0e03873be37fdc96c46f04f06e4035ac697b5f8628efcf7c34ecba01ea3a7d7a
[INFO] running `Command { std: "docker" "start" "-a" "0e03873be37fdc96c46f04f06e4035ac697b5f8628efcf7c34ecba01ea3a7d7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0e03873be37fdc96c46f04f06e4035ac697b5f8628efcf7c34ecba01ea3a7d7a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0e03873be37fdc96c46f04f06e4035ac697b5f8628efcf7c34ecba01ea3a7d7a", kill_on_drop: false }`
[INFO] [stdout] 0e03873be37fdc96c46f04f06e4035ac697b5f8628efcf7c34ecba01ea3a7d7a
[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] 153bf1ddf98cc56b834d9fa5305aaf3d081d0c57ec707186030cca71c2cfd341
[INFO] running `Command { std: "docker" "start" "-a" "153bf1ddf98cc56b834d9fa5305aaf3d081d0c57ec707186030cca71c2cfd341", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.150
[INFO] [stderr]    Compiling libudev-sys v0.1.4
[INFO] [stderr]     Checking bitflags v2.0.2
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking flem v0.6.2
[INFO] [stderr]     Checking nix v0.26.4
[INFO] [stderr]     Checking libudev v0.3.0
[INFO] [stderr]     Checking serialport v4.2.2
[INFO] [stderr]     Checking flem-serial-rs v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:135:9
[INFO] [stdout]     |
[INFO] [stdout] 135 |         self.unlisten();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let _ = self.unlisten();
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:135:9
[INFO] [stdout]     |
[INFO] [stdout] 135 |         self.unlisten();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let _ = self.unlisten();
[INFO] [stdout]     |         +++++++
[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 1.75s
[INFO] running `Command { std: "docker" "inspect" "153bf1ddf98cc56b834d9fa5305aaf3d081d0c57ec707186030cca71c2cfd341", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "153bf1ddf98cc56b834d9fa5305aaf3d081d0c57ec707186030cca71c2cfd341", kill_on_drop: false }`
[INFO] [stdout] 153bf1ddf98cc56b834d9fa5305aaf3d081d0c57ec707186030cca71c2cfd341
[INFO] checking flem-serial-rs-0.3.0 against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] extracting crate flem-serial-rs 0.3.0 into /workspace/builds/worker-7-tc2/source
[INFO] validating manifest of crates.io crate flem-serial-rs 0.3.0 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 flem-serial-rs 0.3.0
[INFO] finished tweaking crates.io crate flem-serial-rs 0.3.0
[INFO] tweaked toml for crates.io crate flem-serial-rs 0.3.0 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] crate crates.io crate flem-serial-rs 0.3.0 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] acd855c941e0d6c94e2df239c4ef4d372d8d8e31a011965c61571a219f6337b1
[INFO] running `Command { std: "docker" "start" "-a" "acd855c941e0d6c94e2df239c4ef4d372d8d8e31a011965c61571a219f6337b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "acd855c941e0d6c94e2df239c4ef4d372d8d8e31a011965c61571a219f6337b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "acd855c941e0d6c94e2df239c4ef4d372d8d8e31a011965c61571a219f6337b1", kill_on_drop: false }`
[INFO] [stdout] acd855c941e0d6c94e2df239c4ef4d372d8d8e31a011965c61571a219f6337b1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 2600d522114728919ebf167e21fd1b115cf16b19bd38fcd8639c1f1725301bea
[INFO] running `Command { std: "docker" "start" "-a" "2600d522114728919ebf167e21fd1b115cf16b19bd38fcd8639c1f1725301bea", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.150
[INFO] [stderr]    Compiling libudev-sys v0.1.4
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking bitflags v2.0.2
[INFO] [stderr]     Checking flem v0.6.2
[INFO] [stderr]     Checking nix v0.26.4
[INFO] [stderr]     Checking libudev v0.3.0
[INFO] [stderr]     Checking serialport v4.2.2
[INFO] [stderr]     Checking flem-serial-rs v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:135:9
[INFO] [stdout]     |
[INFO] [stdout] 135 |         self.unlisten();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let _ = self.unlisten();
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:135:9
[INFO] [stdout]     |
[INFO] [stdout] 135 |         self.unlisten();
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 135 |         let _ = self.unlisten();
[INFO] [stdout]     |         +++++++
[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 1.71s
[INFO] running `Command { std: "docker" "inspect" "2600d522114728919ebf167e21fd1b115cf16b19bd38fcd8639c1f1725301bea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2600d522114728919ebf167e21fd1b115cf16b19bd38fcd8639c1f1725301bea", kill_on_drop: false }`
[INFO] [stdout] 2600d522114728919ebf167e21fd1b115cf16b19bd38fcd8639c1f1725301bea