[INFO] updating cached repository AntoineSebert/local_hack_day_2018
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/AntoineSebert/local_hack_day_2018
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/AntoineSebert/local_hack_day_2018" "work/ex/beta-1.38-1/sources/1.37.0/gh/AntoineSebert/local_hack_day_2018"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/AntoineSebert/local_hack_day_2018'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/AntoineSebert/local_hack_day_2018" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/AntoineSebert/local_hack_day_2018"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/AntoineSebert/local_hack_day_2018'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d2c5e66d2b273bd11288fa8fcfe99e197e319f64
[INFO] sha for GitHub repo AntoineSebert/local_hack_day_2018: d2c5e66d2b273bd11288fa8fcfe99e197e319f64
[INFO] validating manifest of AntoineSebert/local_hack_day_2018 on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of AntoineSebert/local_hack_day_2018 on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing AntoineSebert/local_hack_day_2018
[INFO] finished frobbing AntoineSebert/local_hack_day_2018
[INFO] frobbed toml for AntoineSebert/local_hack_day_2018 written to work/ex/beta-1.38-1/sources/1.37.0/gh/AntoineSebert/local_hack_day_2018/Cargo.toml
[INFO] started frobbing AntoineSebert/local_hack_day_2018
[INFO] finished frobbing AntoineSebert/local_hack_day_2018
[INFO] frobbed toml for AntoineSebert/local_hack_day_2018 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/AntoineSebert/local_hack_day_2018/Cargo.toml
[INFO] crate AntoineSebert/local_hack_day_2018 already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing AntoineSebert/local_hack_day_2018 against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-6/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/AntoineSebert/local_hack_day_2018:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 345c425555526a525393d89c707e6fc3ac7e865019cf274e493c1f4d792f6ee0
[INFO] running `"docker" "start" "-a" "345c425555526a525393d89c707e6fc3ac7e865019cf274e493c1f4d792f6ee0"`
[INFO] [stderr]    Compiling toml v0.4.9
[INFO] [stderr]    Compiling local_hack_day_2018 v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:71:17
[INFO] [stderr]    |
[INFO] [stderr] 71 |             let mut neighbors: u8 = 0;
[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:126:9
[INFO] [stderr]     |
[INFO] [stderr] 126 |     for mut element in cells_to_update.iter_mut() {
[INFO] [stderr]     |         ----^^^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] error[E0502]: cannot borrow `world[_][_]` as immutable because it is also borrowed as mutable
[INFO] [stderr]    --> src/main.rs:114:34
[INFO] [stderr]     |
[INFO] [stderr] 114 |             let is_alive: bool = world[n][n_2].clone(); 
[INFO] [stderr]     |                                  ^^^^^^^^^^^^^ immutable borrow occurs here
[INFO] [stderr] ...
[INFO] [stderr] 121 |                 cells_to_update.push(&mut world[n][n_2]);
[INFO] [stderr]     |                 ---------------      ------------------ mutable borrow occurs here
[INFO] [stderr]     |                 |
[INFO] [stderr]     |                 mutable borrow later used here
[INFO] [stderr] 
[INFO] [stderr] error[E0499]: cannot borrow `world[_][_]` as mutable more than once at a time
[INFO] [stderr]    --> src/main.rs:117:42
[INFO] [stderr]     |
[INFO] [stderr] 117 |                     cells_to_update.push(&mut world[n][n_2]);
[INFO] [stderr]     |                                          ^^^^^^^^^^^^^^^^^^ second mutable borrow occurs here
[INFO] [stderr] ...
[INFO] [stderr] 121 |                 cells_to_update.push(&mut world[n][n_2]);
[INFO] [stderr]     |                                      ------------------ first mutable borrow occurs here
[INFO] [stderr] ...
[INFO] [stderr] 126 |     for mut element in cells_to_update.iter_mut() {
[INFO] [stderr]     |                        --------------- first borrow later used here
[INFO] [stderr] 
[INFO] [stderr] error[E0499]: cannot borrow `world[_][_]` as mutable more than once at a time
[INFO] [stderr]    --> src/main.rs:121:38
[INFO] [stderr]     |
[INFO] [stderr] 121 |                 cells_to_update.push(&mut world[n][n_2]);
[INFO] [stderr]     |                                      ^^^^^^^^^^^^^^^^^^ mutable borrow starts here in previous iteration of loop
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0499, E0502.
[INFO] [stderr] For more information about an error, try `rustc --explain E0499`.
[INFO] [stderr] error: Could not compile `local_hack_day_2018`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "345c425555526a525393d89c707e6fc3ac7e865019cf274e493c1f4d792f6ee0"`
[INFO] running `"docker" "rm" "-f" "345c425555526a525393d89c707e6fc3ac7e865019cf274e493c1f4d792f6ee0"`
[INFO] [stdout] 345c425555526a525393d89c707e6fc3ac7e865019cf274e493c1f4d792f6ee0