[INFO] cloning repository https://github.com/sobersanta/hello-rust
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/sobersanta/hello-rust" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsobersanta%2Fhello-rust", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsobersanta%2Fhello-rust'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] b869da0928681b3e833519615cdad4cdfc11f377
[INFO] checking sobersanta/hello-rust against master#af4a5a13a15fa0c60e06321077ef452f769b42fd for pr-122960-4
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsobersanta%2Fhello-rust" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sobersanta/hello-rust on toolchain af4a5a13a15fa0c60e06321077ef452f769b42fd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sobersanta/hello-rust
[INFO] finished tweaking git repo https://github.com/sobersanta/hello-rust
[INFO] tweaked toml for git repo https://github.com/sobersanta/hello-rust written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/sobersanta/hello-rust already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded pin-project v1.0.3
[INFO] [stderr]   Downloaded syn v1.0.58
[INFO] [stderr]   Downloaded pin-project-internal v1.0.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7165f261ee496ed511a9dd64f0a1cc542c1e03cd2f9f1cc3613c541790a58c96
[INFO] running `Command { std: "docker" "start" "-a" "7165f261ee496ed511a9dd64f0a1cc542c1e03cd2f9f1cc3613c541790a58c96", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7165f261ee496ed511a9dd64f0a1cc542c1e03cd2f9f1cc3613c541790a58c96", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7165f261ee496ed511a9dd64f0a1cc542c1e03cd2f9f1cc3613c541790a58c96", kill_on_drop: false }`
[INFO] [stdout] 7165f261ee496ed511a9dd64f0a1cc542c1e03cd2f9f1cc3613c541790a58c96
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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=allow" "-e" "RUSTDOCFLAGS=--cap-lints=allow" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c95bb8ae353c32cbc14b25cf2040209df746b99283b28776fd45ceb74089a1d8
[INFO] running `Command { std: "docker" "start" "-a" "c95bb8ae353c32cbc14b25cf2040209df746b99283b28776fd45ceb74089a1d8", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.58
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]     Checking futures-sink v0.3.8
[INFO] [stderr]     Checking futures-core v0.3.8
[INFO] [stderr]     Checking once_cell v1.5.2
[INFO] [stderr]     Checking futures-io v0.3.8
[INFO] [stderr]     Checking futures-channel v0.3.8
[INFO] [stderr]     Checking futures-task v0.3.8
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]    Compiling pin-project-internal v1.0.3
[INFO] [stderr]    Compiling futures-macro v0.3.8
[INFO] [stderr]     Checking pin-project v1.0.3
[INFO] [stderr]     Checking futures-util v0.3.8
[INFO] [stderr]     Checking futures-executor v0.3.8
[INFO] [stderr]     Checking futures v0.3.8
[INFO] [stderr]     Checking hello-rust v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0502]: cannot borrow `a` as mutable because it is also borrowed as immutable
[INFO] [stdout]   --> src/exercises/borrow_xxx/mod.rs:36:9
[INFO] [stdout]    |
[INFO] [stdout] 35 |         let y = &a.y;
[INFO] [stdout]    |                 ---- immutable borrow occurs here
[INFO] [stdout] 36 |         a.get_a_mut().xxx(|| String::from(y));
[INFO] [stdout]    |         ^^^^^^^^^^^^^                     - immutable borrow later captured here by closure
[INFO] [stdout]    |         |
[INFO] [stdout]    |         mutable borrow occurs here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0502`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hello-rust` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "c95bb8ae353c32cbc14b25cf2040209df746b99283b28776fd45ceb74089a1d8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c95bb8ae353c32cbc14b25cf2040209df746b99283b28776fd45ceb74089a1d8", kill_on_drop: false }`
[INFO] [stdout] c95bb8ae353c32cbc14b25cf2040209df746b99283b28776fd45ceb74089a1d8