[INFO] cloning repository https://github.com/kajstof/RustCrashCourse
[INFO] running `"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"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkajstof%2FRustCrashCourse'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7775f74297feea7b3aa5604e788118eb5717f33f
[INFO] testing kajstof/RustCrashCourse against beta-2020-06-03 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkajstof%2FRustCrashCourse" "/workspace/builds/worker-1/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kajstof/RustCrashCourse on toolchain beta-2020-06-03
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-1/source/Cargo.toml
[INFO] crate git repo https://github.com/kajstof/RustCrashCourse already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-06-03" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f0cd81f3954c0accb2a7673418c46048000e7f96ddc79fb550175fe1e4205b79
[INFO] running `"docker" "start" "-a" "f0cd81f3954c0accb2a7673418c46048000e7f96ddc79fb550175fe1e4205b79"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling rust_crash_course v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/pointer_ref.rs:14:9
[INFO] [stderr]    |
[INFO] [stderr] 14 |     let mut vec2 = &vec1;
[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] error[E0596]: cannot borrow `*vec2` as mutable, as it is behind a `&` reference
[INFO] [stderr]   --> src/pointer_ref.rs:15:5
[INFO] [stderr]    |
[INFO] [stderr] 14 |     let mut vec2 = &vec1;
[INFO] [stderr]    |                    ----- help: consider changing this to be a mutable reference: `&mut vec1`
[INFO] [stderr] 15 |     vec2.push(5);
[INFO] [stderr]    |     ^^^^ `vec2` is a `&` reference, so the data it refers to cannot be borrowed as mutable
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error; 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0596`.
[INFO] [stderr] error: could not compile `rust_crash_course`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "f0cd81f3954c0accb2a7673418c46048000e7f96ddc79fb550175fe1e4205b79"`
[INFO] running `"docker" "rm" "-f" "f0cd81f3954c0accb2a7673418c46048000e7f96ddc79fb550175fe1e4205b79"`
[INFO] [stdout] f0cd81f3954c0accb2a7673418c46048000e7f96ddc79fb550175fe1e4205b79