[INFO] fetching crate ecdsa_fun 0.6.1...
[INFO] testing ecdsa_fun-0.6.1 against 1.54.0 for beta-1.55-1
[INFO] extracting crate ecdsa_fun 0.6.1 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate ecdsa_fun 0.6.1 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 ecdsa_fun 0.6.1
[INFO] finished tweaking crates.io crate ecdsa_fun 0.6.1
[INFO] tweaked toml for crates.io crate ecdsa_fun 0.6.1 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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 614255415deb9ac61f60a6fc11efe1d0a1c8e628d1ad06e5841977f620767a64
[INFO] running `Command { std: "docker" "start" "-a" "614255415deb9ac61f60a6fc11efe1d0a1c8e628d1ad06e5841977f620767a64", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "614255415deb9ac61f60a6fc11efe1d0a1c8e628d1ad06e5841977f620767a64", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "614255415deb9ac61f60a6fc11efe1d0a1c8e628d1ad06e5841977f620767a64", kill_on_drop: false }`
[INFO] [stdout] 614255415deb9ac61f60a6fc11efe1d0a1c8e628d1ad06e5841977f620767a64
[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] 04fee0e6cbd17a572d78a88e4c672e1afce88f6b5a976165f1c0e8db197609c4
[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" "04fee0e6cbd17a572d78a88e4c672e1afce88f6b5a976165f1c0e8db197609c4", kill_on_drop: false }`
[INFO] [stderr]    Compiling subtle-ng v2.4.1
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]    Compiling secp256k1-sys v0.4.1
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling secp256kfun_parity_backend v0.1.5
[INFO] [stderr]    Compiling secp256kfun v0.6.2
[INFO] [stderr]    Compiling secp256k1 v0.20.3
[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/secp256kfun-0.6.2/src/lib.rs:2:34
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(feature = "nightly", feature(min_specialization, rustc_attrs))]
[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" "04fee0e6cbd17a572d78a88e4c672e1afce88f6b5a976165f1c0e8db197609c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04fee0e6cbd17a572d78a88e4c672e1afce88f6b5a976165f1c0e8db197609c4", kill_on_drop: false }`
[INFO] [stdout] 04fee0e6cbd17a572d78a88e4c672e1afce88f6b5a976165f1c0e8db197609c4
