[INFO] updating cached repository Sporious/Toy-Rust-OS
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Sporious/Toy-Rust-OS
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Sporious/Toy-Rust-OS" "work/ex/beta-1.38-1/sources/1.37.0/gh/Sporious/Toy-Rust-OS"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/Sporious/Toy-Rust-OS'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Sporious/Toy-Rust-OS" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Sporious/Toy-Rust-OS"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Sporious/Toy-Rust-OS'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7f1ed894f7f5810e7e14b34d04bc263dea06b621
[INFO] sha for GitHub repo Sporious/Toy-Rust-OS: 7f1ed894f7f5810e7e14b34d04bc263dea06b621
[INFO] validating manifest of Sporious/Toy-Rust-OS 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 Sporious/Toy-Rust-OS 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 Sporious/Toy-Rust-OS
[INFO] finished frobbing Sporious/Toy-Rust-OS
[INFO] frobbed toml for Sporious/Toy-Rust-OS written to work/ex/beta-1.38-1/sources/1.37.0/gh/Sporious/Toy-Rust-OS/Cargo.toml
[INFO] started frobbing Sporious/Toy-Rust-OS
[INFO] finished frobbing Sporious/Toy-Rust-OS
[INFO] frobbed toml for Sporious/Toy-Rust-OS written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/Sporious/Toy-Rust-OS/Cargo.toml
[INFO] crate Sporious/Toy-Rust-OS 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] testing Sporious/Toy-Rust-OS 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-1/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/Sporious/Toy-Rust-OS:/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] 1ac9e2307c4c6090c5105283a62fe5fb725d7fa2630263afee1044f8f3f5872d
[INFO] running `"docker" "start" "-a" "1ac9e2307c4c6090c5105283a62fe5fb725d7fa2630263afee1044f8f3f5872d"`
[INFO] [stderr] warning: `panic` setting is ignored for `test` profile
[INFO] [stderr]    Compiling rpi_os v0.1.0 (/opt/crater/workdir)
[INFO] [stderr]    Compiling volatile v0.2.4
[INFO] [stderr]    Compiling rlibc v1.0.0
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> src/stdio.rs:84:37
[INFO] [stderr]    |
[INFO] [stderr] 84 |         stdioback.guard_out = true; ///Lock the mutex 
[INFO] [stderr]    |                                     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 85 |         Stdio { stdioback }
[INFO] [stderr]    |         ------------------- rustdoc does not generate documentation for expressions
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]  --> src/lib.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![feature(compiler_builtins_lib, lang_items, asm, pointer_methods, const_fn)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `Iterator`
[INFO] [stderr]  --> src/stdio.rs:4:32
[INFO] [stderr]   |
[INFO] [stderr] 4 | use core::iter::{IntoIterator, Iterator};
[INFO] [stderr]   |                                ^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `ReadOnly`, `WriteOnly`
[INFO] [stderr]  --> src/uart.rs:5:16
[INFO] [stderr]   |
[INFO] [stderr] 5 | use volatile::{ReadOnly, ReadWrite, Volatile, WriteOnly};
[INFO] [stderr]   |                ^^^^^^^^                       ^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `core::sync::atomic::AtomicBool`
[INFO] [stderr]   --> src/lib.rs:36:5
[INFO] [stderr]    |
[INFO] [stderr] 36 | use core::sync::atomic::AtomicBool;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0522]: definition of an unknown language item: `panic_fmt`
[INFO] [stderr]   --> src/lib.rs:50:1
[INFO] [stderr]    |
[INFO] [stderr] 50 | #[lang = "panic_fmt"]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^ definition of unknown language item `panic_fmt`
[INFO] [stderr] 
[INFO] [stderr] error: `#[panic_handler]` function required, but not found
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0522, E0554.
[INFO] [stderr] For more information about an error, try `rustc --explain E0522`.
[INFO] [stderr] error: Could not compile `rpi_os`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "1ac9e2307c4c6090c5105283a62fe5fb725d7fa2630263afee1044f8f3f5872d"`
[INFO] running `"docker" "rm" "-f" "1ac9e2307c4c6090c5105283a62fe5fb725d7fa2630263afee1044f8f3f5872d"`
[INFO] [stdout] 1ac9e2307c4c6090c5105283a62fe5fb725d7fa2630263afee1044f8f3f5872d