[INFO] cloning repository https://github.com/ajms/comprehensive_rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ajms/comprehensive_rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fajms%2Fcomprehensive_rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fajms%2Fcomprehensive_rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4a6e600af94a0c6b955cf30b42a5b6fcfab7e1a7
[INFO] building ajms/comprehensive_rust against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fajms%2Fcomprehensive_rust" "/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/ajms/comprehensive_rust on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ajms/comprehensive_rust
[INFO] finished tweaking git repo https://github.com/ajms/comprehensive_rust
[INFO] tweaked toml for git repo https://github.com/ajms/comprehensive_rust written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/ajms/comprehensive_rust 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ccd2be3adcf63c9f717aadee31641e8703a18829194c06b20b91ce61b42258af
[INFO] running `Command { std: "docker" "start" "-a" "ccd2be3adcf63c9f717aadee31641e8703a18829194c06b20b91ce61b42258af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ccd2be3adcf63c9f717aadee31641e8703a18829194c06b20b91ce61b42258af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ccd2be3adcf63c9f717aadee31641e8703a18829194c06b20b91ce61b42258af", kill_on_drop: false }`
[INFO] [stdout] ccd2be3adcf63c9f717aadee31641e8703a18829194c06b20b91ce61b42258af
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b39604cd3c2a1ac73ae82364c04f6651d75bd74b59ae2cee45b3b5f8cc4b2846
[INFO] running `Command { std: "docker" "start" "-a" "b39604cd3c2a1ac73ae82364c04f6651d75bd74b59ae2cee45b3b5f8cc4b2846", kill_on_drop: false }`
[INFO] [stderr]    Compiling exercise v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `callback` is never read
[INFO] [stdout]   --> src/gui_library.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 43 | pub struct Button {
[INFO] [stdout]    |            ------ field in this struct
[INFO] [stdout] 44 |     label: Label,
[INFO] [stdout] 45 |     callback: Box<dyn FnMut()>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.41s
[INFO] running `Command { std: "docker" "inspect" "b39604cd3c2a1ac73ae82364c04f6651d75bd74b59ae2cee45b3b5f8cc4b2846", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b39604cd3c2a1ac73ae82364c04f6651d75bd74b59ae2cee45b3b5f8cc4b2846", kill_on_drop: false }`
[INFO] [stdout] b39604cd3c2a1ac73ae82364c04f6651d75bd74b59ae2cee45b3b5f8cc4b2846
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] eb23befdb8e39547593d90e568abe7d01cb4d7d7c5cab78552e954df5f58677e
[INFO] running `Command { std: "docker" "start" "-a" "eb23befdb8e39547593d90e568abe7d01cb4d7d7c5cab78552e954df5f58677e", kill_on_drop: false }`
[INFO] [stderr]    Compiling exercise v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `callback` is never read
[INFO] [stdout]   --> src/gui_library.rs:45:5
[INFO] [stdout]    |
[INFO] [stdout] 43 | pub struct Button {
[INFO] [stdout]    |            ------ field in this struct
[INFO] [stdout] 44 |     label: Label,
[INFO] [stdout] 45 |     callback: Box<dyn FnMut()>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.33s
[INFO] running `Command { std: "docker" "inspect" "eb23befdb8e39547593d90e568abe7d01cb4d7d7c5cab78552e954df5f58677e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eb23befdb8e39547593d90e568abe7d01cb4d7d7c5cab78552e954df5f58677e", kill_on_drop: false }`
[INFO] [stdout] eb23befdb8e39547593d90e568abe7d01cb4d7d7c5cab78552e954df5f58677e