[INFO] fetching crate microamp 0.1.0-alpha.7...
[INFO] testing microamp-0.1.0-alpha.7 against 1.100.0-beta.1+cargoflags=--release for beta-release-1.100-2
[INFO] extracting crate microamp 0.1.0-alpha.7 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate microamp 0.1.0-alpha.7
[INFO] finished tweaking crates.io crate microamp 0.1.0-alpha.7
[INFO] tweaked toml for crates.io crate microamp 0.1.0-alpha.7 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate microamp 0.1.0-alpha.7 on toolchain 1.100.0-beta.1
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 5 packages to highest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:77db811e55d90add9212f6832c23229e3de5f1c1f9905e8cb07319ea15df73ac" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] 31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97
[INFO] running `Command { std: "docker" "start" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-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" "-w" "/opt/rustwide/workdir" "--user" "0:0" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "build" "--frozen" "--message-format=json" "--release", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling microamp-macros v0.1.0-alpha.5
[INFO] [stderr]    Compiling microamp v0.1.0-alpha.7 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(auto_traits)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `microamp` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97", kill_on_drop: false }`
[INFO] [stdout] 31bf97d19051ba5f3ec7a1d502484cbf1706db1eaf4590b6edc86192773edb97
