[INFO] fetching crate rpn-c 0.2.1...
[INFO] testing rpn-c-0.2.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate rpn-c 0.2.1 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate rpn-c 0.2.1 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] removed /workspace/builds/worker-12/source/.cargo/config.toml
[INFO] started tweaking crates.io crate rpn-c 0.2.1
[INFO] finished tweaking crates.io crate rpn-c 0.2.1
[INFO] tweaked toml for crates.io crate rpn-c 0.2.1 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate rpn-c 0.2.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded logos v0.12.0
[INFO] [stderr]   Downloaded beef v0.5.0
[INFO] [stderr]   Downloaded logos-derive v0.12.0
[INFO] [stderr]   Downloaded ieee754 v0.2.6
[INFO] [stderr]   Downloaded rustc-cfg v0.4.0
[INFO] [stderr]   Downloaded ramp v0.6.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] 8603f38718d9833a0dcfc1edbe9cfcc960a5bc28fb0cd06735b7bc61f168858c
[INFO] running `Command { std: "docker" "start" "-a" "8603f38718d9833a0dcfc1edbe9cfcc960a5bc28fb0cd06735b7bc61f168858c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8603f38718d9833a0dcfc1edbe9cfcc960a5bc28fb0cd06735b7bc61f168858c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8603f38718d9833a0dcfc1edbe9cfcc960a5bc28fb0cd06735b7bc61f168858c", kill_on_drop: false }`
[INFO] [stdout] 8603f38718d9833a0dcfc1edbe9cfcc960a5bc28fb0cd06735b7bc61f168858c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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] ce7e536607a9e0d31d685720375411d883e9889bbd09d2c5b1d739840c360e53
[INFO] running `Command { std: "docker" "start" "-a" "ce7e536607a9e0d31d685720375411d883e9889bbd09d2c5b1d739840c360e53", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling libc v0.2.91
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.64
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling gimli v0.23.0
[INFO] [stderr]    Compiling object v0.23.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling rustc-demangle v0.1.20
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling cc v1.0.67
[INFO] [stderr]    Compiling beef v0.5.0
[INFO] [stderr]    Compiling regex-syntax v0.6.23
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]    Compiling ieee754 v0.2.6
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling hamming v0.1.3
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling crossbeam-utils v0.8.3
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling memoffset v0.6.3
[INFO] [stderr]    Compiling num-bigint v0.4.0
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.3
[INFO] [stderr]    Compiling crossbeam-channel v0.5.0
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling addr2line v0.14.1
[INFO] [stderr]    Compiling backtrace v0.3.57
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling logos-derive v0.12.0
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling rustc-cfg v0.4.0
[INFO] [stderr]    Compiling ramp v0.6.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/ramp-0.6.0/src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(core_intrinsics, asm, allocator_api)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/ramp-0.6.0/src/lib.rs:18:1
[INFO] [stdout]    |
[INFO] [stdout] 18 | #![feature(step_trait, ptr_internals, raw_vec_internals)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling logos v0.12.0
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ramp` due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "ce7e536607a9e0d31d685720375411d883e9889bbd09d2c5b1d739840c360e53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce7e536607a9e0d31d685720375411d883e9889bbd09d2c5b1d739840c360e53", kill_on_drop: false }`
[INFO] [stdout] ce7e536607a9e0d31d685720375411d883e9889bbd09d2c5b1d739840c360e53