[INFO] fetching crate komodo_airdrop 0.0.2...
[INFO] testing komodo_airdrop-0.0.2 against 1.49.0 for beta-1.50-1
[INFO] extracting crate komodo_airdrop 0.0.2 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate komodo_airdrop 0.0.2 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate komodo_airdrop 0.0.2
[INFO] finished tweaking crates.io crate komodo_airdrop 0.0.2
[INFO] tweaked toml for crates.io crate komodo_airdrop 0.0.2 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--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-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8bbdea72c1773100469ad6dff597c46af884e8b45cf8b3718e0d7de0f419775c
[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" "8bbdea72c1773100469ad6dff597c46af884e8b45cf8b3718e0d7de0f419775c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8bbdea72c1773100469ad6dff597c46af884e8b45cf8b3718e0d7de0f419775c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bbdea72c1773100469ad6dff597c46af884e8b45cf8b3718e0d7de0f419775c", kill_on_drop: false }`
[INFO] [stdout] 8bbdea72c1773100469ad6dff597c46af884e8b45cf8b3718e0d7de0f419775c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", 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] bd7e0c877dc7a190372a3efc95685f9ad2f6e0a3e2ba878ae5e4b1cb31fd737c
[INFO] running `Command { std: "docker" "start" "-a" "bd7e0c877dc7a190372a3efc95685f9ad2f6e0a3e2ba878ae5e4b1cb31fd737c", kill_on_drop: false }`
[INFO] [stderr]    Compiling cc v1.0.26
[INFO] [stderr]    Compiling os_info v1.3.3
[INFO] [stderr]    Compiling bech32 v0.5.0
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]    Compiling serde_urlencoded v0.5.5
[INFO] [stderr]    Compiling derive_more v0.14.1
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling bitcoin-bech32 v0.8.1
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]    Compiling openssl-sys v0.9.60
[INFO] [stderr]    Compiling secp256k1 v0.11.6
[INFO] [stderr]    Compiling cookie_store v0.7.0
[INFO] [stderr]    Compiling openssl v0.10.32
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling bitcoin v0.14.2
[INFO] [stderr]    Compiling hyper-tls v0.3.2
[INFO] [stderr]    Compiling reqwest v0.9.24
[INFO] [stderr]    Compiling komodo_rpc_client v0.1.2
[INFO] [stderr]    Compiling komodo_airdrop v0.0.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:40:1
[INFO] [stdout]    |
[INFO] [stdout] 40 | #![feature(drain_filter)]
[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 `komodo_airdrop`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "bd7e0c877dc7a190372a3efc95685f9ad2f6e0a3e2ba878ae5e4b1cb31fd737c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bd7e0c877dc7a190372a3efc95685f9ad2f6e0a3e2ba878ae5e4b1cb31fd737c", kill_on_drop: false }`
[INFO] [stdout] bd7e0c877dc7a190372a3efc95685f9ad2f6e0a3e2ba878ae5e4b1cb31fd737c