[INFO] cloning repository https://github.com/Bravo555/category-theory-for-programmers
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Bravo555/category-theory-for-programmers" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBravo555%2Fcategory-theory-for-programmers", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBravo555%2Fcategory-theory-for-programmers'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 76332543a5ef9b6acf5d5991f5c387a682aa2840
[INFO] checking Bravo555/category-theory-for-programmers against master#33fdb797f59421c7bbecaa4588ed5d7a31a9494a for pr-87190-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBravo555%2Fcategory-theory-for-programmers" "/workspace/builds/worker-19/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-19/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Bravo555/category-theory-for-programmers on toolchain 33fdb797f59421c7bbecaa4588ed5d7a31a9494a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Bravo555/category-theory-for-programmers
[INFO] finished tweaking git repo https://github.com/Bravo555/category-theory-for-programmers
[INFO] tweaked toml for git repo https://github.com/Bravo555/category-theory-for-programmers written to /workspace/builds/worker-19/source/Cargo.toml
[INFO] crate git repo https://github.com/Bravo555/category-theory-for-programmers already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "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-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e3623e09b057aca10a1204bafac9b8a39884620901913faa43529c626f359eea
[INFO] running `Command { std: "docker" "start" "-a" "e3623e09b057aca10a1204bafac9b8a39884620901913faa43529c626f359eea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e3623e09b057aca10a1204bafac9b8a39884620901913faa43529c626f359eea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3623e09b057aca10a1204bafac9b8a39884620901913faa43529c626f359eea", kill_on_drop: false }`
[INFO] [stdout] e3623e09b057aca10a1204bafac9b8a39884620901913faa43529c626f359eea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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" "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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+33fdb797f59421c7bbecaa4588ed5d7a31a9494a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] aa9589cc92ef5d53d8cb0c5eb14b3031b6437afe4ef54c378c1e0d82e4a9cef8
[INFO] running `Command { std: "docker" "start" "-a" "aa9589cc92ef5d53d8cb0c5eb14b3031b6437afe4ef54c378c1e0d82e4a9cef8", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.85
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking rand_core v0.6.1
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]     Checking excercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function is never used: `ret`
[INFO] [stdout]  --> src/bin/ch4.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn ret<A>(a: A) -> Optional<A> {
[INFO] [stdout]   |    ^^^
[INFO] [stdout]   |
[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: function is never used: `ret`
[INFO] [stdout]  --> src/bin/ch4.rs:7:4
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn ret<A>(a: A) -> Optional<A> {
[INFO] [stdout]   |    ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 13.16s
[INFO] running `Command { std: "docker" "inspect" "aa9589cc92ef5d53d8cb0c5eb14b3031b6437afe4ef54c378c1e0d82e4a9cef8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aa9589cc92ef5d53d8cb0c5eb14b3031b6437afe4ef54c378c1e0d82e4a9cef8", kill_on_drop: false }`
[INFO] [stdout] aa9589cc92ef5d53d8cb0c5eb14b3031b6437afe4ef54c378c1e0d82e4a9cef8