[INFO] cloning repository https://github.com/kajstof/RustCrashCourse
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/kajstof/RustCrashCourse" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkajstof%2FRustCrashCourse", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkajstof%2FRustCrashCourse'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7775f74297feea7b3aa5604e788118eb5717f33f
[INFO] checking kajstof/RustCrashCourse against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkajstof%2FRustCrashCourse" "/workspace/builds/worker-8/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kajstof/RustCrashCourse on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/kajstof/RustCrashCourse
[INFO] finished tweaking git repo https://github.com/kajstof/RustCrashCourse
[INFO] tweaked toml for git repo https://github.com/kajstof/RustCrashCourse written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/kajstof/RustCrashCourse already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a9de7e0720da0aea95a35dbf8d8966de4d38ee2bb62367f885f57615b38f2821
[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" "a9de7e0720da0aea95a35dbf8d8966de4d38ee2bb62367f885f57615b38f2821", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a9de7e0720da0aea95a35dbf8d8966de4d38ee2bb62367f885f57615b38f2821", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a9de7e0720da0aea95a35dbf8d8966de4d38ee2bb62367f885f57615b38f2821", kill_on_drop: false }`
[INFO] [stdout] a9de7e0720da0aea95a35dbf8d8966de4d38ee2bb62367f885f57615b38f2821
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6b4714b7c1af5ea013e457229d26f5e979c99b242bb4b575b5ef16842e6b2714
[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" "6b4714b7c1af5ea013e457229d26f5e979c99b242bb4b575b5ef16842e6b2714", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking rust_crash_course v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/pointer_ref.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut vec2 = &vec1;
[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] error[E0596]: cannot borrow `*vec2` as mutable, as it is behind a `&` reference
[INFO] [stdout]   --> src/pointer_ref.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut vec2 = &vec1;
[INFO] [stdout]    |                    ----- help: consider changing this to be a mutable reference: `&mut vec1`
[INFO] [stdout] 15 |     vec2.push(5);
[INFO] [stdout]    |     ^^^^ `vec2` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0596`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_crash_course`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/pointer_ref.rs:14:9
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut vec2 = &vec1;
[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] error[E0596]: cannot borrow `*vec2` as mutable, as it is behind a `&` reference
[INFO] [stdout]   --> src/pointer_ref.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 14 |     let mut vec2 = &vec1;
[INFO] [stdout]    |                    ----- help: consider changing this to be a mutable reference: `&mut vec1`
[INFO] [stdout] 15 |     vec2.push(5);
[INFO] [stdout]    |     ^^^^ `vec2` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0596`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "6b4714b7c1af5ea013e457229d26f5e979c99b242bb4b575b5ef16842e6b2714", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b4714b7c1af5ea013e457229d26f5e979c99b242bb4b575b5ef16842e6b2714", kill_on_drop: false }`
[INFO] [stdout] 6b4714b7c1af5ea013e457229d26f5e979c99b242bb4b575b5ef16842e6b2714