[INFO] cloning repository https://github.com/bobbyng626/course-add-drop
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/bobbyng626/course-add-drop" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbobbyng626%2Fcourse-add-drop", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbobbyng626%2Fcourse-add-drop'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] abac3f9e8fdc75f2609e2aa2c5b70b361aa6093e
[INFO] testing bobbyng626/course-add-drop against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbobbyng626%2Fcourse-add-drop" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/bobbyng626/course-add-drop on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/bobbyng626/course-add-drop
[INFO] finished tweaking git repo https://github.com/bobbyng626/course-add-drop
[INFO] tweaked toml for git repo https://github.com/bobbyng626/course-add-drop written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/bobbyng626/course-add-drop already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 37b7380bdfb4ac33650260cf5ec26437a40c0af0ae846d4eb07c4e75997a081c
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "37b7380bdfb4ac33650260cf5ec26437a40c0af0ae846d4eb07c4e75997a081c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "37b7380bdfb4ac33650260cf5ec26437a40c0af0ae846d4eb07c4e75997a081c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37b7380bdfb4ac33650260cf5ec26437a40c0af0ae846d4eb07c4e75997a081c", kill_on_drop: false }`
[INFO] [stdout] 37b7380bdfb4ac33650260cf5ec26437a40c0af0ae846d4eb07c4e75997a081c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6a2aab3f4da85a84ce901932a5d61aa745ea603338be13050a16f20c7589762b
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "6a2aab3f4da85a84ce901932a5d61aa745ea603338be13050a16f20c7589762b", kill_on_drop: false }`
[INFO] [stderr]    Compiling course-add-drop v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:292:17
[INFO] [stdout]     |
[INFO] [stdout] 292 |             let mut total_credit: i32 = student.credit + course.credit.to_string().parse::<i32>().unwrap();
[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 [unoptimized + debuginfo] target(s) in 3.38s
[INFO] running `Command { std: "docker" "inspect" "6a2aab3f4da85a84ce901932a5d61aa745ea603338be13050a16f20c7589762b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6a2aab3f4da85a84ce901932a5d61aa745ea603338be13050a16f20c7589762b", kill_on_drop: false }`
[INFO] [stdout] 6a2aab3f4da85a84ce901932a5d61aa745ea603338be13050a16f20c7589762b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b4f306d1c0fce62f135ec5bc8164fe9d3734274cc5aff0ac920b42dfcb3fd12a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b4f306d1c0fce62f135ec5bc8164fe9d3734274cc5aff0ac920b42dfcb3fd12a", kill_on_drop: false }`
[INFO] [stderr]    Compiling course-add-drop v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:292:17
[INFO] [stdout]     |
[INFO] [stdout] 292 |             let mut total_credit: i32 = student.credit + course.credit.to_string().parse::<i32>().unwrap();
[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] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 1.23s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "b4f306d1c0fce62f135ec5bc8164fe9d3734274cc5aff0ac920b42dfcb3fd12a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b4f306d1c0fce62f135ec5bc8164fe9d3734274cc5aff0ac920b42dfcb3fd12a", kill_on_drop: false }`
[INFO] [stdout] b4f306d1c0fce62f135ec5bc8164fe9d3734274cc5aff0ac920b42dfcb3fd12a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 03110f29a33aeaf1a95430b303258182ee5cf0a17f38eb4aba635a69f66930f9
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "03110f29a33aeaf1a95430b303258182ee5cf0a17f38eb4aba635a69f66930f9", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stdout] running 0 tests
[INFO] [stderr]    --> src/main.rs:292:17
[INFO] [stdout] 
[INFO] [stderr]     |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 292 |             let mut total_credit: i32 = student.credit + course.credit.to_string().parse::<i32>().unwrap();
[INFO] [stdout] 
[INFO] [stderr]     |                 ----^^^^^^^^^^^^
[INFO] [stderr]     |                 |
[INFO] [stderr]     |                 help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: `course-add-drop` (bin "course-add-drop" test) generated 1 warning
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/course_add_drop-c2cde2fb5ea3b262)
[INFO] running `Command { std: "docker" "inspect" "03110f29a33aeaf1a95430b303258182ee5cf0a17f38eb4aba635a69f66930f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "03110f29a33aeaf1a95430b303258182ee5cf0a17f38eb4aba635a69f66930f9", kill_on_drop: false }`
[INFO] [stdout] 03110f29a33aeaf1a95430b303258182ee5cf0a17f38eb4aba635a69f66930f9