[INFO] cloning repository https://github.com/hoodie/rust-workshop-chat
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hoodie/rust-workshop-chat" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoodie%2Frust-workshop-chat", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoodie%2Frust-workshop-chat'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b7f9af6d1f8d963765a0a00784d2259b9171bf68
[INFO] checking hoodie/rust-workshop-chat against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoodie%2Frust-workshop-chat" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hoodie/rust-workshop-chat 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 git repo https://github.com/hoodie/rust-workshop-chat
[INFO] finished tweaking git repo https://github.com/hoodie/rust-workshop-chat
[INFO] tweaked toml for git repo https://github.com/hoodie/rust-workshop-chat written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/hoodie/rust-workshop-chat 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 color-backtrace v0.3.0
[INFO] [stderr]   Downloaded object v0.28.4
[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] 0bad457ca2e2dbe2e411cf6e586541eeb4edee7a827f16652ad343a4a13d3a3a
[INFO] running `Command { std: "docker" "start" "-a" "0bad457ca2e2dbe2e411cf6e586541eeb4edee7a827f16652ad343a4a13d3a3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0bad457ca2e2dbe2e411cf6e586541eeb4edee7a827f16652ad343a4a13d3a3a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0bad457ca2e2dbe2e411cf6e586541eeb4edee7a827f16652ad343a4a13d3a3a", kill_on_drop: false }`
[INFO] [stdout] 0bad457ca2e2dbe2e411cf6e586541eeb4edee7a827f16652ad343a4a13d3a3a
[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] 5bee0bf2b897ec982d14f69f75e4f6b0af3b6afbdb5e2447c2caa3862e7dd8ed
[INFO] running `Command { std: "docker" "start" "-a" "5bee0bf2b897ec982d14f69f75e4f6b0af3b6afbdb5e2447c2caa3862e7dd8ed", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling unicode-ident v1.0.1
[INFO] [stderr]    Compiling syn v1.0.96
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]    Compiling serde_derive v1.0.137
[INFO] [stderr]     Checking gimli v0.26.1
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking miniz_oxide v0.5.3
[INFO] [stderr]     Checking regex-syntax v0.6.26
[INFO] [stderr]     Checking rustc-demangle v0.1.21
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]     Checking object v0.28.4
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]    Compiling backtrace v0.3.65
[INFO] [stderr]     Checking addr2line v0.17.0
[INFO] [stderr]     Checking regex v1.5.6
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking color-backtrace v0.3.0
[INFO] [stderr]     Checking workshop-chat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variant `Close` is never constructed
[INFO] [stdout]   --> examples/server2.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | enum PeerMessage {
[INFO] [stdout]    |      ----------- variant in this enum
[INFO] [stdout] 28 |     Message { content: String },
[INFO] [stdout] 29 |     Close,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `PeerMessage` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `handler` is never read
[INFO] [stdout]   --> examples/server2.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 34 | struct Server<T: MsgHandler> {
[INFO] [stdout]    |        ------ field in this struct
[INFO] [stdout] 35 |     addr: String,
[INFO] [stdout] 36 |     handler: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Close` is never constructed
[INFO] [stdout]   --> examples/server.rs:30:5
[INFO] [stdout]    |
[INFO] [stdout] 28 | enum PeerMessage {
[INFO] [stdout]    |      ----------- variant in this enum
[INFO] [stdout] 29 |     Message { content: String },
[INFO] [stdout] 30 |     Close,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `PeerMessage` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning 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 23.14s
[INFO] running `Command { std: "docker" "inspect" "5bee0bf2b897ec982d14f69f75e4f6b0af3b6afbdb5e2447c2caa3862e7dd8ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bee0bf2b897ec982d14f69f75e4f6b0af3b6afbdb5e2447c2caa3862e7dd8ed", kill_on_drop: false }`
[INFO] [stdout] 5bee0bf2b897ec982d14f69f75e4f6b0af3b6afbdb5e2447c2caa3862e7dd8ed
[INFO] checking hoodie/rust-workshop-chat against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhoodie%2Frust-workshop-chat" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hoodie/rust-workshop-chat 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 git repo https://github.com/hoodie/rust-workshop-chat
[INFO] finished tweaking git repo https://github.com/hoodie/rust-workshop-chat
[INFO] tweaked toml for git repo https://github.com/hoodie/rust-workshop-chat written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/hoodie/rust-workshop-chat 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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] e84e8cbdf098d0e16cc171611bac9eeff09b6b68d2e465cbda3a45e6c66930ed
[INFO] running `Command { std: "docker" "start" "-a" "e84e8cbdf098d0e16cc171611bac9eeff09b6b68d2e465cbda3a45e6c66930ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e84e8cbdf098d0e16cc171611bac9eeff09b6b68d2e465cbda3a45e6c66930ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e84e8cbdf098d0e16cc171611bac9eeff09b6b68d2e465cbda3a45e6c66930ed", kill_on_drop: false }`
[INFO] [stdout] e84e8cbdf098d0e16cc171611bac9eeff09b6b68d2e465cbda3a45e6c66930ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 314d63f502a0d4d866f1814f0338417cfeada6e2f6761d7caea22c493472a2fc
[INFO] running `Command { std: "docker" "start" "-a" "314d63f502a0d4d866f1814f0338417cfeada6e2f6761d7caea22c493472a2fc", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling libc v0.2.126
[INFO] [stderr]    Compiling proc-macro2 v1.0.39
[INFO] [stderr]    Compiling unicode-ident v1.0.1
[INFO] [stderr]    Compiling syn v1.0.96
[INFO] [stderr]    Compiling cc v1.0.73
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]     Checking gimli v0.26.1
[INFO] [stderr]    Compiling serde_derive v1.0.137
[INFO] [stderr]     Checking miniz_oxide v0.5.3
[INFO] [stderr]     Checking regex-syntax v0.6.26
[INFO] [stderr]    Compiling serde v1.0.137
[INFO] [stderr]     Checking rustc-demangle v0.1.21
[INFO] [stderr]     Checking aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.18
[INFO] [stderr]     Checking object v0.28.4
[INFO] [stderr]    Compiling backtrace v0.3.65
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking addr2line v0.17.0
[INFO] [stderr]     Checking regex v1.5.6
[INFO] [stderr]     Checking color-backtrace v0.3.0
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking workshop-chat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variant `Close` is never constructed
[INFO] [stdout]   --> examples/server.rs:30:5
[INFO] [stdout]    |
[INFO] [stdout] 28 | enum PeerMessage {
[INFO] [stdout]    |      ----------- variant in this enum
[INFO] [stdout] 29 |     Message { content: String },
[INFO] [stdout] 30 |     Close,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `PeerMessage` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Close` is never constructed
[INFO] [stdout]   --> examples/server2.rs:29:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | enum PeerMessage {
[INFO] [stdout]    |      ----------- variant in this enum
[INFO] [stdout] 28 |     Message { content: String },
[INFO] [stdout] 29 |     Close,
[INFO] [stdout]    |     ^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `PeerMessage` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `handler` is never read
[INFO] [stdout]   --> examples/server2.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 34 | struct Server<T: MsgHandler> {
[INFO] [stdout]    |        ------ field in this struct
[INFO] [stdout] 35 |     addr: String,
[INFO] [stdout] 36 |     handler: T,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 24.19s
[INFO] running `Command { std: "docker" "inspect" "314d63f502a0d4d866f1814f0338417cfeada6e2f6761d7caea22c493472a2fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "314d63f502a0d4d866f1814f0338417cfeada6e2f6761d7caea22c493472a2fc", kill_on_drop: false }`
[INFO] [stdout] 314d63f502a0d4d866f1814f0338417cfeada6e2f6761d7caea22c493472a2fc