[INFO] crate ramp 0.5.2 is already in cache
[INFO] testing ramp-0.5.2 against 1.38.0 for beta-1.39-1
[INFO] extracting crate ramp 0.5.2 into work/builds/worker-4/source
[INFO] validating manifest of crates.io crate ramp 0.5.2 on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate ramp 0.5.2
[INFO] finished tweaking crates.io crate ramp 0.5.2
[INFO] tweaked toml for crates.io crate ramp 0.5.2 written to work/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate ramp 0.5.2 already has a lockfile, it will not be regenerated
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 1b993295a3b45be8aed90f201e31e07094e2d98abe98991028fbc037f92a6411
[INFO] running `"docker" "start" "-a" "1b993295a3b45be8aed90f201e31e07094e2d98abe98991028fbc037f92a6411"`
[INFO] [stderr]    Compiling num-traits v0.1.40
[INFO] [stderr]    Compiling libc v0.2.29
[INFO] [stderr]    Compiling rustc-cfg v0.2.0
[INFO] [stderr]    Compiling cc v1.0.17
[INFO] [stderr]    Compiling rand_core v0.2.1
[INFO] [stderr]    Compiling hamming v0.1.3
[INFO] [stderr]    Compiling ieee754 v0.2.2
[INFO] [stderr]    Compiling rand v0.3.16
[INFO] [stderr]    Compiling rand v0.5.4
[INFO] [stderr]    Compiling num-integer v0.1.35
[INFO] [stderr]    Compiling num-bigint v0.1.40
[INFO] [stderr]    Compiling ramp v0.5.2 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:18:1
[INFO] [stderr]    |
[INFO] [stderr] 18 | #![feature(core_intrinsics, asm, allocator_api)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:19:1
[INFO] [stderr]    |
[INFO] [stderr] 19 | #![feature(step_trait, ptr_internals, raw_vec_internals)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `ramp`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "1b993295a3b45be8aed90f201e31e07094e2d98abe98991028fbc037f92a6411"`
[INFO] running `"docker" "rm" "-f" "1b993295a3b45be8aed90f201e31e07094e2d98abe98991028fbc037f92a6411"`
[INFO] [stdout] 1b993295a3b45be8aed90f201e31e07094e2d98abe98991028fbc037f92a6411