[INFO] fetching crate rtsam 0.1.2...
[INFO] testing rtsam-0.1.2 against 1.55.0 for beta-1.56-1
[INFO] extracting crate rtsam 0.1.2 into /workspace/builds/worker-48/source
[INFO] validating manifest of crates.io crate rtsam 0.1.2 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rtsam 0.1.2
[INFO] finished tweaking crates.io crate rtsam 0.1.2
[INFO] tweaked toml for crates.io crate rtsam 0.1.2 written to /workspace/builds/worker-48/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded alga v0.8.2
[INFO] [stderr]   Downloaded finitediff v0.1.4
[INFO] [stderr]   Downloaded nalgebra v0.17.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-48/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-48/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c4144a39f3e8ac2b4b5b78ba2114103b34279bfb65e94aff99a0ca011c2ab3ac
[INFO] running `Command { std: "docker" "start" "-a" "c4144a39f3e8ac2b4b5b78ba2114103b34279bfb65e94aff99a0ca011c2ab3ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c4144a39f3e8ac2b4b5b78ba2114103b34279bfb65e94aff99a0ca011c2ab3ac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c4144a39f3e8ac2b4b5b78ba2114103b34279bfb65e94aff99a0ca011c2ab3ac", kill_on_drop: false }`
[INFO] [stdout] c4144a39f3e8ac2b4b5b78ba2114103b34279bfb65e94aff99a0ca011c2ab3ac
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-48/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-48/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 581c9df3fb14559a81ad30dc3ad9873f49317ac3cfa024fde6fff7e3cb5fe981
[INFO] running `Command { std: "docker" "start" "-a" "581c9df3fb14559a81ad30dc3ad9873f49317ac3cfa024fde6fff7e3cb5fe981", kill_on_drop: false }`
[INFO] [stderr]    Compiling libm v0.1.4
[INFO] [stderr]    Compiling rawpointer v0.2.1
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling matrixmultiply v0.2.4
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling alga v0.8.2
[INFO] [stderr]    Compiling nalgebra v0.17.3
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling rtsam v0.1.2 (/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(alloc)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rtsam` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "581c9df3fb14559a81ad30dc3ad9873f49317ac3cfa024fde6fff7e3cb5fe981", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "581c9df3fb14559a81ad30dc3ad9873f49317ac3cfa024fde6fff7e3cb5fe981", kill_on_drop: false }`
[INFO] [stdout] 581c9df3fb14559a81ad30dc3ad9873f49317ac3cfa024fde6fff7e3cb5fe981