[INFO] fetching crate secp256kfun 0.1.5...
[INFO] testing secp256kfun-0.1.5 against 1.45.2 for beta-1.46-1
[INFO] extracting crate secp256kfun 0.1.5 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate secp256kfun 0.1.5 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate secp256kfun 0.1.5
[INFO] finished tweaking crates.io crate secp256kfun 0.1.5
[INFO] tweaked toml for crates.io crate secp256kfun 0.1.5 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate secp256kfun 0.1.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 11fcb1159950ec4848c43176a98c3fcab9e2a1fff85348e0820254666d5f8786
[INFO] running `Command { std: "docker" "start" "-a" "11fcb1159950ec4848c43176a98c3fcab9e2a1fff85348e0820254666d5f8786", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "11fcb1159950ec4848c43176a98c3fcab9e2a1fff85348e0820254666d5f8786", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "11fcb1159950ec4848c43176a98c3fcab9e2a1fff85348e0820254666d5f8786", kill_on_drop: false }`
[INFO] [stdout] 11fcb1159950ec4848c43176a98c3fcab9e2a1fff85348e0820254666d5f8786
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b3d3b1d638f661e41dd61c9979ac4703872ef4fb4a81a429ffac30fc65f606cc
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b3d3b1d638f661e41dd61c9979ac4703872ef4fb4a81a429ffac30fc65f606cc", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling subtle v2.2.3
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling block-padding v0.1.5
[INFO] [stderr]    Compiling secp256kfun_parity_backend v0.1.1
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling secp256kfun v0.1.5 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling sha2 v0.8.2
[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(rustc_attrs, min_specialization, external_doc)]
[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 `secp256kfun`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "b3d3b1d638f661e41dd61c9979ac4703872ef4fb4a81a429ffac30fc65f606cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b3d3b1d638f661e41dd61c9979ac4703872ef4fb4a81a429ffac30fc65f606cc", kill_on_drop: false }`
[INFO] [stdout] b3d3b1d638f661e41dd61c9979ac4703872ef4fb4a81a429ffac30fc65f606cc