[INFO] fetching crate incinerator 0.0.1...
[INFO] testing incinerator-0.0.1 against 1.45.2 for beta-1.46-1
[INFO] extracting crate incinerator 0.0.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate incinerator 0.0.1 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate incinerator 0.0.1
[INFO] finished tweaking crates.io crate incinerator 0.0.1
[INFO] tweaked toml for crates.io crate incinerator 0.0.1 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] fabba39fe0f6b138ccfa20cc4e8430d0ac000e6787697cfb8863fc96b74ba399
[INFO] running `Command { std: "docker" "start" "-a" "fabba39fe0f6b138ccfa20cc4e8430d0ac000e6787697cfb8863fc96b74ba399", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fabba39fe0f6b138ccfa20cc4e8430d0ac000e6787697cfb8863fc96b74ba399", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fabba39fe0f6b138ccfa20cc4e8430d0ac000e6787697cfb8863fc96b74ba399", kill_on_drop: false }`
[INFO] [stdout] fabba39fe0f6b138ccfa20cc4e8430d0ac000e6787697cfb8863fc96b74ba399
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5197f97c4b38d0f7442994c3827a48d68628d0829f306da15836f20c399638a7
[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" "5197f97c4b38d0f7442994c3827a48d68628d0829f306da15836f20c399638a7", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.37
[INFO] [stderr]    Compiling instant v0.1.6
[INFO] [stderr]    Compiling smallvec v1.4.1
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling nested v0.1.1
[INFO] [stderr]    Compiling once_cell v1.4.0
[INFO] [stderr]    Compiling lock_api v0.4.1
[INFO] [stderr]    Compiling parking_lot_core v0.8.0
[INFO] [stderr]    Compiling parking_lot v0.11.0
[INFO] [stderr]    Compiling atomic_enum v0.1.1
[INFO] [stderr]    Compiling incinerator v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | / #![feature(
[INFO] [stdout] 2 | |     alloc_layout_extra,
[INFO] [stdout] 3 | |     cell_update,
[INFO] [stdout] 4 | |     raw,
[INFO] [stdout] 5 | |     maybe_uninit_ref,
[INFO] [stdout] 6 | |     maybe_uninit_extra
[INFO] [stdout] 7 | | )]
[INFO] [stdout]   | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: the `#[track_caller]` attribute is an experimental feature
[INFO] [stdout]    --> segment.rs:200:1
[INFO] [stdout]     |
[INFO] [stdout] 200 | #[track_caller]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #47809 <https://github.com/rust-lang/rust/issues/47809> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0658]: use of unstable library feature 'leading_trailing_ones'
[INFO] [stdout]    --> bitmap.rs:186:30
[INFO] [stdout]     |
[INFO] [stdout] 186 |         let new_bitidx = val.trailing_ones() as u64 - 1;
[INFO] [stdout]     |                              ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #57969 <https://github.com/rust-lang/rust/issues/57969> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0658.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `incinerator`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "5197f97c4b38d0f7442994c3827a48d68628d0829f306da15836f20c399638a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5197f97c4b38d0f7442994c3827a48d68628d0829f306da15836f20c399638a7", kill_on_drop: false }`
[INFO] [stdout] 5197f97c4b38d0f7442994c3827a48d68628d0829f306da15836f20c399638a7