[INFO] fetching crate thinnbox 0.1.2...
[INFO] testing thinnbox-0.1.2 against 1.91.0 for beta-1.92-2
[INFO] extracting crate thinnbox 0.1.2 into /workspace/builds/worker-6-tc1/source
[INFO] started tweaking crates.io crate thinnbox 0.1.2
[INFO] finished tweaking crates.io crate thinnbox 0.1.2
[INFO] tweaked toml for crates.io crate thinnbox 0.1.2 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate thinnbox 0.1.2 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "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" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 22 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded docfg v0.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6b5a3f09e62ae05c88ddf73596f375645c3235e01a74ac7437ba791dc4589c4e
[INFO] running `Command { std: "docker" "start" "-a" "6b5a3f09e62ae05c88ddf73596f375645c3235e01a74ac7437ba791dc4589c4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b5a3f09e62ae05c88ddf73596f375645c3235e01a74ac7437ba791dc4589c4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b5a3f09e62ae05c88ddf73596f375645c3235e01a74ac7437ba791dc4589c4e", kill_on_drop: false }`
[INFO] [stdout] 6b5a3f09e62ae05c88ddf73596f375645c3235e01a74ac7437ba791dc4589c4e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d873f29da54efe2210525891c0bbda5c2dbf7d017ccc2f4ec10ca4bf2972f542
[INFO] running `Command { std: "docker" "start" "-a" "d873f29da54efe2210525891c0bbda5c2dbf7d017ccc2f4ec10ca4bf2972f542", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.103
[INFO] [stderr]    Compiling quote v1.0.41
[INFO] [stderr]    Compiling unicode-ident v1.0.22
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling docfg v0.1.0
[INFO] [stderr]    Compiling thinnbox v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:1:1
[INFO] [stdout]    |
[INFO] [stdout]  1 | / #![feature(
[INFO] [stdout]  2 | |     ptr_metadata,
[INFO] [stdout]  3 | |     unsize,
[INFO] [stdout]  4 | |     alloc_layout_extra,
[INFO] [stdout] ...  |
[INFO] [stdout] 10 | |     tuple_trait
[INFO] [stdout] 11 | | )]
[INFO] [stdout]    | |__^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `$i::*`
[INFO] [stdout]   --> src/lib.rs:23:21
[INFO] [stdout]    |
[INFO] [stdout] 23 |             pub use $i::*;
[INFO] [stdout]    |                     ^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 37 | flat_mod! { r#fn, iter, ops, future, ser_de, io }
[INFO] [stdout]    | ------------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout]    = note: this warning originates in the macro `flat_mod` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `pointer_byte_offsets` has been stable since 1.75.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     pointer_byte_offsets,
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `thinnbox` (lib) due to 1 previous error; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "d873f29da54efe2210525891c0bbda5c2dbf7d017ccc2f4ec10ca4bf2972f542", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d873f29da54efe2210525891c0bbda5c2dbf7d017ccc2f4ec10ca4bf2972f542", kill_on_drop: false }`
[INFO] [stdout] d873f29da54efe2210525891c0bbda5c2dbf7d017ccc2f4ec10ca4bf2972f542