[INFO] fetching crate mantle-test 0.2.0...
[INFO] testing mantle-test-0.2.0 against 1.59.0 for beta-1.60-1
[INFO] extracting crate mantle-test 0.2.0 into /workspace/builds/worker-64/source
[INFO] validating manifest of crates.io crate mantle-test 0.2.0 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 mantle-test 0.2.0
[INFO] finished tweaking crates.io crate mantle-test 0.2.0
[INFO] tweaked toml for crates.io crate mantle-test 0.2.0 written to /workspace/builds/worker-64/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] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "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-64/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/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] 0c25e387acc346e20b3e859d6055f6d85aadb72a5f211e0d1f20f95696a57429
[INFO] running `Command { std: "docker" "start" "-a" "0c25e387acc346e20b3e859d6055f6d85aadb72a5f211e0d1f20f95696a57429", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0c25e387acc346e20b3e859d6055f6d85aadb72a5f211e0d1f20f95696a57429", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0c25e387acc346e20b3e859d6055f6d85aadb72a5f211e0d1f20f95696a57429", kill_on_drop: false }`
[INFO] [stdout] 0c25e387acc346e20b3e859d6055f6d85aadb72a5f211e0d1f20f95696a57429
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/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] ef76fe294409147d4037a6a06704099d31b62b1e955a819d35e5c059a6fa7dfc
[INFO] running `Command { std: "docker" "start" "-a" "ef76fe294409147d4037a6a06704099d31b62b1e955a819d35e5c059a6fa7dfc", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling anyhow v1.0.55
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling hex v0.4.3
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling hex v0.3.2
[INFO] [stderr]    Compiling tiny-keccak v1.5.0
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling quote v1.0.15
[INFO] [stderr]    Compiling proc-quote-impl v0.2.2
[INFO] [stderr]    Compiling thiserror-impl v1.0.30
[INFO] [stderr]    Compiling proc-quote v0.2.2
[INFO] [stderr]    Compiling thiserror v1.0.30
[INFO] [stderr]    Compiling derive_more v0.15.0
[INFO] [stderr]    Compiling mantle-macros v0.2.1
[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/mantle-macros-0.2.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_diagnostic, type_ascription)]
[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 `mantle-macros` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "ef76fe294409147d4037a6a06704099d31b62b1e955a819d35e5c059a6fa7dfc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef76fe294409147d4037a6a06704099d31b62b1e955a819d35e5c059a6fa7dfc", kill_on_drop: false }`
[INFO] [stdout] ef76fe294409147d4037a6a06704099d31b62b1e955a819d35e5c059a6fa7dfc