Dec 02 12:31:26.656 INFO testing un_algebra-0.1.4 against 1.30.1 for beta-1.31-5
Dec 02 12:31:26.656 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.31-5/worker-1/1.30.1:/target:rw,Z" "-v" "/mnt/big/crater/work/local/test-source/worker-1/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 12:31:26.884 INFO [stdout] 2d5b64c3b9ae1ca57ceab5ec89ccde7c6ce4fdb6f63936f311b4f4c96d4c3de2
Dec 02 12:31:26.887 INFO running `"docker" "start" "-a" "2d5b64c3b9ae1ca57ceab5ec89ccde7c6ce4fdb6f63936f311b4f4c96d4c3de2"`
Dec 02 12:31:27.393 INFO [stderr] usermod: no changes
Dec 02 12:31:27.567 INFO [stderr]    Compiling bit-set v0.5.0
Dec 02 12:31:27.567 INFO [stderr]    Compiling float-cmp v0.4.0
Dec 02 12:31:27.567 INFO [stderr]    Compiling wait-timeout v0.1.5
Dec 02 12:31:27.567 INFO [stderr]    Compiling rand v0.5.5
Dec 02 12:31:27.567 INFO [stderr]    Compiling num-bigint v0.2.1
Dec 02 12:31:29.683 INFO [stderr]    Compiling rusty-fork v0.2.1
Dec 02 12:31:32.872 INFO [stderr]    Compiling num-rational v0.2.1
Dec 02 12:31:33.202 INFO [stderr]    Compiling proptest v0.8.7
Dec 02 12:31:35.385 INFO [stderr]    Compiling num v0.2.0
Dec 02 12:31:48.582 INFO [stderr]    Compiling un_algebra v0.1.4 (/source)
Dec 02 12:31:50.695 INFO [stderr] error[E0554]: #![feature] may not be used on the stable release channel
Dec 02 12:31:50.695 INFO [stderr]  --> src/lib.rs:1:1
Dec 02 12:31:50.695 INFO [stderr]   |
Dec 02 12:31:50.695 INFO [stderr] 1 | #![feature(external_doc)]
Dec 02 12:31:50.695 INFO [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 02 12:31:50.699 INFO [stderr] 
Dec 02 12:31:50.699 INFO [stderr] error: aborting due to previous error
Dec 02 12:31:50.699 INFO [stderr] 
Dec 02 12:31:50.699 INFO [stderr] For more information about this error, try `rustc --explain E0554`.
Dec 02 12:31:50.705 INFO [stderr] error: Could not compile `un_algebra`.
Dec 02 12:31:50.705 INFO [stderr] 
Dec 02 12:31:50.705 INFO [stderr] To learn more, run the command again with --verbose.
Dec 02 12:31:50.705 INFO [stderr] su: No module specific data is present
Dec 02 12:31:50.944 INFO running `"docker" "inspect" "2d5b64c3b9ae1ca57ceab5ec89ccde7c6ce4fdb6f63936f311b4f4c96d4c3de2"`
Dec 02 12:31:51.116 INFO running `"docker" "rm" "-f" "2d5b64c3b9ae1ca57ceab5ec89ccde7c6ce4fdb6f63936f311b4f4c96d4c3de2"`
Dec 02 12:31:51.267 INFO [stdout] 2d5b64c3b9ae1ca57ceab5ec89ccde7c6ce4fdb6f63936f311b4f4c96d4c3de2