[INFO] fetching crate iter-opt-filter 0.1.0...
[INFO] testing iter-opt-filter-0.1.0 against 1.59.0 for beta-1.60-1
[INFO] extracting crate iter-opt-filter 0.1.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate iter-opt-filter 0.1.0 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate iter-opt-filter 0.1.0
[INFO] finished tweaking crates.io crate iter-opt-filter 0.1.0
[INFO] tweaked toml for crates.io crate iter-opt-filter 0.1.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 27276e49d77136aafeedc59c962d2783ed51cf0d79d5a3e9e3c68ae46c5bc1e6
[INFO] running `Command { std: "docker" "start" "-a" "27276e49d77136aafeedc59c962d2783ed51cf0d79d5a3e9e3c68ae46c5bc1e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "27276e49d77136aafeedc59c962d2783ed51cf0d79d5a3e9e3c68ae46c5bc1e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "27276e49d77136aafeedc59c962d2783ed51cf0d79d5a3e9e3c68ae46c5bc1e6", kill_on_drop: false }`
[INFO] [stdout] 27276e49d77136aafeedc59c962d2783ed51cf0d79d5a3e9e3c68ae46c5bc1e6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a2a985efedd659ea32eb1f8ef87a04af4aa5ca3c27798170184b8369389bbe54
[INFO] running `Command { std: "docker" "start" "-a" "a2a985efedd659ea32eb1f8ef87a04af4aa5ca3c27798170184b8369389bbe54", kill_on_drop: false }`
[INFO] [stderr]    Compiling iter-opt-filter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.91s
[INFO] running `Command { std: "docker" "inspect" "a2a985efedd659ea32eb1f8ef87a04af4aa5ca3c27798170184b8369389bbe54", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a2a985efedd659ea32eb1f8ef87a04af4aa5ca3c27798170184b8369389bbe54", kill_on_drop: false }`
[INFO] [stdout] a2a985efedd659ea32eb1f8ef87a04af4aa5ca3c27798170184b8369389bbe54
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 61cb2aed060f7b36add6108331c3c82bd3849ce8dca6c7afeb4b6f9fb971f6b4
[INFO] running `Command { std: "docker" "start" "-a" "61cb2aed060f7b36add6108331c3c82bd3849ce8dca6c7afeb4b6f9fb971f6b4", kill_on_drop: false }`
[INFO] [stderr]    Compiling iter-opt-filter v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:11:27
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![cfg_attr(test, feature(test))]
[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 `iter-opt-filter` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "61cb2aed060f7b36add6108331c3c82bd3849ce8dca6c7afeb4b6f9fb971f6b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "61cb2aed060f7b36add6108331c3c82bd3849ce8dca6c7afeb4b6f9fb971f6b4", kill_on_drop: false }`
[INFO] [stdout] 61cb2aed060f7b36add6108331c3c82bd3849ce8dca6c7afeb4b6f9fb971f6b4