Dec 02 05:50:54.732 INFO testing Lireer/ricochet-robot-solver against 1.30.1 for beta-1.31-5
Dec 02 05:50:54.732 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.31-5/worker-2/1.30.1:/target:rw,Z" "-v" "/mnt/big/crater/work/local/test-source/worker-2/beta-1.31-5/1.30.1:/source:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/source" "-e" "USER_ID=1000" "-e" "CMD=cargo +1.30.1 build --frozen" "-e" "CARGO_TARGET_DIR=/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/cargo-home" "-e" "RUSTUP_HOME=/rustup-home" "-m" "1536M" "--network" "none" "crater"`
Dec 02 05:50:55.079 INFO [stdout] fb3635bc313e968a60ba71bb4c8156d7e319c20aa5688d308870b1f0292f6d0b
Dec 02 05:50:55.083 INFO running `"docker" "start" "-a" "fb3635bc313e968a60ba71bb4c8156d7e319c20aa5688d308870b1f0292f6d0b"`
Dec 02 05:50:56.432 INFO [stderr] usermod: no changes
Dec 02 05:50:56.527 INFO [stderr]    Compiling num-complex v0.1.36
Dec 02 05:50:56.535 INFO [stderr]    Compiling ricochet_board v0.1.0 (/source/ricochet_board)
Dec 02 05:50:56.535 INFO [stderr]    Compiling num-bigint v0.1.36
Dec 02 05:50:58.407 INFO [stderr] warning: variable does not need to be mutable
Dec 02 05:50:58.407 INFO [stderr]    --> ricochet_board/src/lib.rs:261:19
Dec 02 05:50:58.407 INFO [stderr]     |
Dec 02 05:50:58.407 INFO [stderr] 261 |     fn fmt(&self, mut fmt: &mut fmt::Formatter) -> fmt::Result {
Dec 02 05:50:58.407 INFO [stderr]     |                   ----^^^
Dec 02 05:50:58.407 INFO [stderr]     |                   |
Dec 02 05:50:58.407 INFO [stderr]     |                   help: remove this `mut`
Dec 02 05:50:58.407 INFO [stderr]     |
Dec 02 05:50:58.407 INFO [stderr]     = note: #[warn(unused_mut)] on by default
Dec 02 05:50:58.407 INFO [stderr] 
Dec 02 05:50:58.415 INFO [stderr] warning: variable does not need to be mutable
Dec 02 05:50:58.415 INFO [stderr]    --> ricochet_board/src/lib.rs:272:19
Dec 02 05:50:58.415 INFO [stderr]     |
Dec 02 05:50:58.416 INFO [stderr] 272 |     fn fmt(&self, mut fmt: &mut fmt::Formatter) -> fmt::Result {
Dec 02 05:50:58.416 INFO [stderr]     |                   ----^^^
Dec 02 05:50:58.416 INFO [stderr]     |                   |
Dec 02 05:50:58.416 INFO [stderr]     |                   help: remove this `mut`
Dec 02 05:50:58.419 INFO [stderr] 
Dec 02 05:50:59.814 INFO [stderr]    Compiling num-rational v0.1.36
Dec 02 05:51:00.795 INFO [stderr]    Compiling num v0.1.37
Dec 02 05:51:01.483 INFO [stderr]    Compiling ricochet_solver v0.1.0 (/source/ricochet_solver)
Dec 02 05:51:02.415 INFO [stderr] error[E0554]: #![feature] may not be used on the stable release channel
Dec 02 05:51:02.415 INFO [stderr]  --> ricochet_solver/src/lib.rs:1:1
Dec 02 05:51:02.415 INFO [stderr]   |
Dec 02 05:51:02.415 INFO [stderr] 1 | #![feature(box_syntax)]
Dec 02 05:51:02.415 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
Dec 02 05:51:02.415 INFO [stderr] 
Dec 02 05:51:02.415 INFO [stderr] error: aborting due to previous error
Dec 02 05:51:02.415 INFO [stderr] 
Dec 02 05:51:02.415 INFO [stderr] For more information about this error, try `rustc --explain E0554`.
Dec 02 05:51:02.415 INFO [stderr] error: Could not compile `ricochet_solver`.
Dec 02 05:51:02.415 INFO [stderr] 
Dec 02 05:51:02.415 INFO [stderr] To learn more, run the command again with --verbose.
Dec 02 05:51:02.415 INFO [stderr] su: No module specific data is present
Dec 02 05:51:03.006 INFO running `"docker" "inspect" "fb3635bc313e968a60ba71bb4c8156d7e319c20aa5688d308870b1f0292f6d0b"`
Dec 02 05:51:03.118 INFO running `"docker" "rm" "-f" "fb3635bc313e968a60ba71bb4c8156d7e319c20aa5688d308870b1f0292f6d0b"`
Dec 02 05:51:03.224 INFO [stdout] fb3635bc313e968a60ba71bb4c8156d7e319c20aa5688d308870b1f0292f6d0b