[INFO] fetching crate rkdb 0.4.0...
[INFO] testing rkdb-0.4.0 against 1.54.0 for beta-1.55-1
[INFO] extracting crate rkdb 0.4.0 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate rkdb 0.4.0 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rkdb 0.4.0
[INFO] finished tweaking crates.io crate rkdb 0.4.0
[INFO] tweaked toml for crates.io crate rkdb 0.4.0 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e49817b07dcd9a0fbae0f76dad7ed574cf96aea8e477747b898e73122df35d49
[INFO] running `Command { std: "docker" "start" "-a" "e49817b07dcd9a0fbae0f76dad7ed574cf96aea8e477747b898e73122df35d49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e49817b07dcd9a0fbae0f76dad7ed574cf96aea8e477747b898e73122df35d49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e49817b07dcd9a0fbae0f76dad7ed574cf96aea8e477747b898e73122df35d49", kill_on_drop: false }`
[INFO] [stdout] e49817b07dcd9a0fbae0f76dad7ed574cf96aea8e477747b898e73122df35d49
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] baa2a212d7b1659541011c4754f40a986960f1dc9a727748a1b8182d25599745
[INFO] running `Command { std: "docker" "start" "-a" "baa2a212d7b1659541011c4754f40a986960f1dc9a727748a1b8182d25599745", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling nix v0.11.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling syn v0.14.9
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling rkdb v0.4.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(lang_items, box_patterns)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `types::*`
[INFO] [stdout]  --> src/kapi.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use types::*;
[INFO] [stdout]   |     ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary braces around function argument
[INFO] [stdout]    --> src/kbindings.rs:256:20
[INFO] [stdout]     |
[INFO] [stdout] 256 |     unsafe { &*kb( { if b { 1 } else { 0 } } ) }
[INFO] [stdout]     |                    ^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these braces
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_braces)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rkdb`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "baa2a212d7b1659541011c4754f40a986960f1dc9a727748a1b8182d25599745", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "baa2a212d7b1659541011c4754f40a986960f1dc9a727748a1b8182d25599745", kill_on_drop: false }`
[INFO] [stdout] baa2a212d7b1659541011c4754f40a986960f1dc9a727748a1b8182d25599745
