[INFO] fetching crate microamp 0.1.0-alpha.5...
[INFO] testing microamp-0.1.0-alpha.5 against 1.47.0 for beta-1.48-1
[INFO] extracting crate microamp 0.1.0-alpha.5 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate microamp 0.1.0-alpha.5 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate microamp 0.1.0-alpha.5
[INFO] finished tweaking crates.io crate microamp 0.1.0-alpha.5
[INFO] tweaked toml for crates.io crate microamp 0.1.0-alpha.5 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", 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] f1b7eb0bb5ae21c524fd68a0216b87d850c2aa846b90c7d40e2f6c62e23960f1
[INFO] running `Command { std: "docker" "start" "-a" "f1b7eb0bb5ae21c524fd68a0216b87d850c2aa846b90c7d40e2f6c62e23960f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f1b7eb0bb5ae21c524fd68a0216b87d850c2aa846b90c7d40e2f6c62e23960f1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1b7eb0bb5ae21c524fd68a0216b87d850c2aa846b90c7d40e2f6c62e23960f1", kill_on_drop: false }`
[INFO] [stdout] f1b7eb0bb5ae21c524fd68a0216b87d850c2aa846b90c7d40e2f6c62e23960f1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d84d3d6e123bf48990e627971e88a1aa176ff496a9461cce264d4ac5a05620a1
[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" "d84d3d6e123bf48990e627971e88a1aa176ff496a9461cce264d4ac5a05620a1", kill_on_drop: false }`
[INFO] [stderr]    Compiling microamp-macros v0.1.0-alpha.5
[INFO] [stderr]    Compiling microamp v0.1.0-alpha.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(external_doc)]
[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:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(optin_builtin_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:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(negative_impls)]
[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 `microamp`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "d84d3d6e123bf48990e627971e88a1aa176ff496a9461cce264d4ac5a05620a1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d84d3d6e123bf48990e627971e88a1aa176ff496a9461cce264d4ac5a05620a1", kill_on_drop: false }`
[INFO] [stdout] d84d3d6e123bf48990e627971e88a1aa176ff496a9461cce264d4ac5a05620a1
