[INFO] updating cached repository https://github.com/jmacmahon/rust-playground
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d3ad60100e7e7cc92aa7af86552948d100656ef3
[INFO] testing jmacmahon/rust-playground against beta-2019-09-28 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjmacmahon%2Frust-playground" "work/builds/worker-0/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jmacmahon/rust-playground on toolchain beta-2019-09-28
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/jmacmahon/rust-playground
[INFO] finished tweaking git repo https://github.com/jmacmahon/rust-playground
[INFO] tweaked toml for git repo https://github.com/jmacmahon/rust-playground written to work/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/jmacmahon/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+beta-2019-09-28" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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-2019-09-28" "build" "--frozen"`
[INFO] [stdout] e0c7a14136d9c65368d34893b50323756c6b0cce12784f6b666802456b536014
[INFO] running `"docker" "start" "-a" "e0c7a14136d9c65368d34893b50323756c6b0cce12784f6b666802456b536014"`
[INFO] [stderr]    Compiling scratch v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused variable: `z`
[INFO] [stderr]  --> src/main.rs:4:9
[INFO] [stderr]   |
[INFO] [stderr] 4 |     let z = &x;
[INFO] [stderr]   |         ^ help: consider prefixing with an underscore: `_z`
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:12:10
[INFO] [stderr]    |
[INFO] [stderr] 12 | fn test2(x: &i32) -> () {
[INFO] [stderr]    |          ^ help: consider prefixing with an underscore: `_x`
[INFO] [stderr] 
[INFO] [stderr] error[E0502]: cannot borrow `x` as immutable because it is also borrowed as mutable
[INFO] [stderr]  --> src/main.rs:4:13
[INFO] [stderr]   |
[INFO] [stderr] 3 |     let y = &mut x;
[INFO] [stderr]   |             ------ mutable borrow occurs here
[INFO] [stderr] 4 |     let z = &x;
[INFO] [stderr]   |             ^^ immutable borrow occurs here
[INFO] [stderr] 5 |     println!("{:?}", y);
[INFO] [stderr]   |                      - mutable borrow later used here
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0502`.
[INFO] [stderr] error: could not compile `scratch`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "e0c7a14136d9c65368d34893b50323756c6b0cce12784f6b666802456b536014"`
[INFO] running `"docker" "rm" "-f" "e0c7a14136d9c65368d34893b50323756c6b0cce12784f6b666802456b536014"`
[INFO] [stdout] e0c7a14136d9c65368d34893b50323756c6b0cce12784f6b666802456b536014