[INFO] fetching crate optimal-core 0.0.0...
[INFO] testing optimal-core-0.0.0 against 1.76.0 for beta-1.77-1
[INFO] extracting crate optimal-core 0.0.0 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate optimal-core 0.0.0 on toolchain 1.76.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate optimal-core 0.0.0
[INFO] finished tweaking crates.io crate optimal-core 0.0.0
[INFO] tweaked toml for crates.io crate optimal-core 0.0.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded blanket v0.3.0
[INFO] [stderr]   Downloaded replace_with v0.1.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7bd72ab7965a5047e1e4d2bbf0a0119b2639bccc770f93038b93ea9f4638c767
[INFO] running `Command { std: "docker" "start" "-a" "7bd72ab7965a5047e1e4d2bbf0a0119b2639bccc770f93038b93ea9f4638c767", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7bd72ab7965a5047e1e4d2bbf0a0119b2639bccc770f93038b93ea9f4638c767", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7bd72ab7965a5047e1e4d2bbf0a0119b2639bccc770f93038b93ea9f4638c767", kill_on_drop: false }`
[INFO] [stdout] 7bd72ab7965a5047e1e4d2bbf0a0119b2639bccc770f93038b93ea9f4638c767
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4a08e92cdc7252e604a89ea12b07182e0ee18af26c515a5862b284872c2793dd
[INFO] running `Command { std: "docker" "start" "-a" "4a08e92cdc7252e604a89ea12b07182e0ee18af26c515a5862b284872c2793dd", kill_on_drop: false }`
[INFO] [stderr]    Compiling streaming-iterator v0.1.9
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling blanket v0.3.0
[INFO] [stderr]    Compiling optimal-core v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.36s
[INFO] running `Command { std: "docker" "inspect" "4a08e92cdc7252e604a89ea12b07182e0ee18af26c515a5862b284872c2793dd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a08e92cdc7252e604a89ea12b07182e0ee18af26c515a5862b284872c2793dd", kill_on_drop: false }`
[INFO] [stdout] 4a08e92cdc7252e604a89ea12b07182e0ee18af26c515a5862b284872c2793dd
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 46d92bf3d29a3b506912ce052383f32a3798d0f01d834efe0c45667917e7f495
[INFO] running `Command { std: "docker" "start" "-a" "46d92bf3d29a3b506912ce052383f32a3798d0f01d834efe0c45667917e7f495", kill_on_drop: false }`
[INFO] [stderr]    Compiling replace_with v0.1.7
[INFO] [stderr]    Compiling static_assertions v1.1.0
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling serde_derive v1.0.196
[INFO] [stderr]    Compiling blanket v0.3.0
[INFO] [stderr]    Compiling optimal-core v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling serde v1.0.196
[INFO] [stderr]    Compiling serde_json v1.0.113
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:19
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![cfg_attr(test, feature(unboxed_closures))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:19
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![cfg_attr(test, feature(fn_traits))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:27
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![cfg_attr(test, feature(fn_traits))]
[INFO] [stdout]   |                           ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `optimal-core` (lib test) due to 4 previous errors
[INFO] running `Command { std: "docker" "inspect" "46d92bf3d29a3b506912ce052383f32a3798d0f01d834efe0c45667917e7f495", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "46d92bf3d29a3b506912ce052383f32a3798d0f01d834efe0c45667917e7f495", kill_on_drop: false }`
[INFO] [stdout] 46d92bf3d29a3b506912ce052383f32a3798d0f01d834efe0c45667917e7f495
