[INFO] updating cached repository https://github.com/Bkindmonk/RustPractice
[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] dddc1c842ad316fb93f1f4a3a9741aea4ff490c9
[INFO] testing Bkindmonk/RustPractice against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FBkindmonk%2FRustPractice" "work/builds/worker-8/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Bkindmonk/RustPractice on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/Bkindmonk/RustPractice
[INFO] finished tweaking git repo https://github.com/Bkindmonk/RustPractice
[INFO] tweaked toml for git repo https://github.com/Bkindmonk/RustPractice written to work/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/Bkindmonk/RustPractice already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-8/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" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 1377eaa411726825826d2756e13a052cfe6f4a877af142de6c261861a5e5943e
[INFO] running `"docker" "start" "-a" "1377eaa411726825826d2756e13a052cfe6f4a877af142de6c261861a5e5943e"`
[INFO] [stderr]    Compiling mergesort v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:91:13
[INFO] [stderr]    |
[INFO] [stderr] 91 |         let mut realhalves = (*real).split_at_mut(halflength);
[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] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:92:13
[INFO] [stderr]    |
[INFO] [stderr] 92 |         let mut scratchhalves = (*scratch).split_at_mut(halflength);
[INFO] [stderr]    |             ----^^^^^^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.51s
[INFO] running `"docker" "inspect" "1377eaa411726825826d2756e13a052cfe6f4a877af142de6c261861a5e5943e"`
[INFO] running `"docker" "rm" "-f" "1377eaa411726825826d2756e13a052cfe6f4a877af142de6c261861a5e5943e"`
[INFO] [stdout] 1377eaa411726825826d2756e13a052cfe6f4a877af142de6c261861a5e5943e
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-8/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" "+1.38.0" "test" "--frozen" "--no-run"`
[INFO] [stdout] 66b5ce28082f88e4059affb723fb5dcc14b0c803af5cf1cdb317bc9c58867db4
[INFO] running `"docker" "start" "-a" "66b5ce28082f88e4059affb723fb5dcc14b0c803af5cf1cdb317bc9c58867db4"`
[INFO] [stderr]    Compiling mergesort v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:91:13
[INFO] [stderr]    |
[INFO] [stderr] 91 |         let mut realhalves = (*real).split_at_mut(halflength);
[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] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:92:13
[INFO] [stderr]    |
[INFO] [stderr] 92 |         let mut scratchhalves = (*scratch).split_at_mut(halflength);
[INFO] [stderr]    |             ----^^^^^^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.16s
[INFO] running `"docker" "inspect" "66b5ce28082f88e4059affb723fb5dcc14b0c803af5cf1cdb317bc9c58867db4"`
[INFO] running `"docker" "rm" "-f" "66b5ce28082f88e4059affb723fb5dcc14b0c803af5cf1cdb317bc9c58867db4"`
[INFO] [stdout] 66b5ce28082f88e4059affb723fb5dcc14b0c803af5cf1cdb317bc9c58867db4
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-8/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" "+1.38.0" "test" "--frozen"`
[INFO] [stdout] 596d4549052812ad63a02928b2b02e8a66a2d9bf1c52358d098d9622dc19c5be
[INFO] running `"docker" "start" "-a" "596d4549052812ad63a02928b2b02e8a66a2d9bf1c52358d098d9622dc19c5be"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.07s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/mergesort-d30de0eb82a25798
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `"docker" "inspect" "596d4549052812ad63a02928b2b02e8a66a2d9bf1c52358d098d9622dc19c5be"`
[INFO] running `"docker" "rm" "-f" "596d4549052812ad63a02928b2b02e8a66a2d9bf1c52358d098d9622dc19c5be"`
[INFO] [stdout] 596d4549052812ad63a02928b2b02e8a66a2d9bf1c52358d098d9622dc19c5be