[INFO] updating cached repository Mec-iS/rust-algos-illuminated
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Mec-iS/rust-algos-illuminated
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Mec-iS/rust-algos-illuminated" "work/ex/beta-1.38-1/sources/1.37.0/gh/Mec-iS/rust-algos-illuminated"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Mec-iS/rust-algos-illuminated'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Mec-iS/rust-algos-illuminated" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mec-iS/rust-algos-illuminated"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mec-iS/rust-algos-illuminated'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e9b7e2a77cfe1d878f4b30043b1e25a1561476db
[INFO] sha for GitHub repo Mec-iS/rust-algos-illuminated: e9b7e2a77cfe1d878f4b30043b1e25a1561476db
[INFO] validating manifest of Mec-iS/rust-algos-illuminated 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 Mec-iS/rust-algos-illuminated 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 Mec-iS/rust-algos-illuminated
[INFO] finished frobbing Mec-iS/rust-algos-illuminated
[INFO] frobbed toml for Mec-iS/rust-algos-illuminated written to work/ex/beta-1.38-1/sources/1.37.0/gh/Mec-iS/rust-algos-illuminated/Cargo.toml
[INFO] started frobbing Mec-iS/rust-algos-illuminated
[INFO] finished frobbing Mec-iS/rust-algos-illuminated
[INFO] frobbed toml for Mec-iS/rust-algos-illuminated written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Mec-iS/rust-algos-illuminated/Cargo.toml
[INFO] crate Mec-iS/rust-algos-illuminated 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 Mec-iS/rust-algos-illuminated 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-4/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/Mec-iS/rust-algos-illuminated:/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] df21c21534e70b7dd2a57ea29edfae195287bd4c1fe06c987dd5691c98133c96
[INFO] running `"docker" "start" "-a" "df21c21534e70b7dd2a57ea29edfae195287bd4c1fe06c987dd5691c98133c96"`
[INFO] [stderr]    Compiling rust-algos-illuminated v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: struct is never constructed: `Queue`
[INFO] [stderr]  --> src/other/mod.rs:5:1
[INFO] [stderr]   |
[INFO] [stderr] 5 | pub struct Queue {
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `push`
[INFO] [stderr]   --> src/other/mod.rs:12:5
[INFO] [stderr]    |
[INFO] [stderr] 12 |     pub fn push(&mut self, element: char) -> () {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop_raw`
[INFO] [stderr]   --> src/other/mod.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     pub fn pop_raw(&mut self) -> Option<char> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `pop_swap`
[INFO] [stderr]   --> src/other/mod.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn pop_swap(&mut self) -> Option<char> {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `split`
[INFO] [stderr]   --> src/other/mod.rs:55:5
[INFO] [stderr]    |
[INFO] [stderr] 55 |     pub fn split(self) -> (Vec<char>, Vec<char>) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/other/mod.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     pub fn new() -> Queue {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(test)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `rust-algos-illuminated`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "df21c21534e70b7dd2a57ea29edfae195287bd4c1fe06c987dd5691c98133c96"`
[INFO] running `"docker" "rm" "-f" "df21c21534e70b7dd2a57ea29edfae195287bd4c1fe06c987dd5691c98133c96"`
[INFO] [stdout] df21c21534e70b7dd2a57ea29edfae195287bd4c1fe06c987dd5691c98133c96