[INFO] cloning repository https://github.com/GrayStrider/playground-rust-book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/GrayStrider/playground-rust-book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7cdd4fbf815c78dcad736bc6612e34c91abb7615
[INFO] checking GrayStrider/playground-rust-book against beta-2020-07-24 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/GrayStrider/playground-rust-book on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/GrayStrider/playground-rust-book
[INFO] finished tweaking git repo https://github.com/GrayStrider/playground-rust-book
[INFO] tweaked toml for git repo https://github.com/GrayStrider/playground-rust-book written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/GrayStrider/playground-rust-book already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 69e6ab7835e9436ecb84001b8ad9da22bb08bdbb658d1bd8f80f7e86c663dd74
[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" "69e6ab7835e9436ecb84001b8ad9da22bb08bdbb658d1bd8f80f7e86c663dd74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "69e6ab7835e9436ecb84001b8ad9da22bb08bdbb658d1bd8f80f7e86c663dd74", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "69e6ab7835e9436ecb84001b8ad9da22bb08bdbb658d1bd8f80f7e86c663dd74", kill_on_drop: false }`
[INFO] [stdout] 69e6ab7835e9436ecb84001b8ad9da22bb08bdbb658d1bd8f80f7e86c663dd74
[INFO] running `Command { std: "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" "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:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 83d40d3b274e7a29d744fd87c8f02262988368de73772024af4e3a6dbdc95454
[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" "83d40d3b274e7a29d744fd87c8f02262988368de73772024af4e3a6dbdc95454", kill_on_drop: false }`
[INFO] [stderr]     Checking play3 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/funcs.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut x: &str = "";
[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[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/ownership_ref_and_borrow.rs:61:3
[INFO] [stdout]    |
[INFO] [stdout] 59 |     for i in &v {
[INFO] [stdout]    |              --
[INFO] [stdout]    |              |
[INFO] [stdout]    |              immutable borrow occurs here
[INFO] [stdout]    |              immutable borrow later used here
[INFO] [stdout] 60 |         println!("{}", i);
[INFO] [stdout] 61 |         v.push(34);
[INFO] [stdout]    |         ^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/funcs.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 |     let mut x: &str = "";
[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: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0502`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `play3`.
[INFO] [stdout] error[E0502]: cannot borrow `v` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/ownership_ref_and_borrow.rs:61:3
[INFO] [stdout]    |
[INFO] [stdout] 59 |     for i in &v {
[INFO] [stdout]    |              --
[INFO] [stdout]    |              |
[INFO] [stdout]    |              immutable borrow occurs here
[INFO] [stdout]    |              immutable borrow later used here
[INFO] [stdout] 60 |         println!("{}", i);
[INFO] [stdout] 61 |         v.push(34);
[INFO] [stdout]    |         ^^^^^^^^^^ mutable borrow occurs here
[INFO] [stdout] 
[INFO] [stdout] 
[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] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0502`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "83d40d3b274e7a29d744fd87c8f02262988368de73772024af4e3a6dbdc95454", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "83d40d3b274e7a29d744fd87c8f02262988368de73772024af4e3a6dbdc95454", kill_on_drop: false }`
[INFO] [stdout] 83d40d3b274e7a29d744fd87c8f02262988368de73772024af4e3a6dbdc95454
