[INFO] fetching crate rusty-p4 0.1.0-alpha.2...
[INFO] documenting rusty-p4-0.1.0-alpha.2 against 1.76.0 for beta-1.77-rustdoc-1
[INFO] extracting crate rusty-p4 0.1.0-alpha.2 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate rusty-p4 0.1.0-alpha.2 on toolchain 1.76.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rusty-p4 0.1.0-alpha.2
[INFO] finished tweaking crates.io crate rusty-p4 0.1.0-alpha.2
[INFO] tweaked toml for crates.io crate rusty-p4 0.1.0-alpha.2 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.76.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded prost-types v0.5.0
[INFO] [stderr]   Downloaded pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]   Downloaded prost v0.5.0
[INFO] [stderr]   Downloaded tokio-fs v0.2.0-alpha.5
[INFO] [stderr]   Downloaded futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded grpcio-compiler v0.5.0
[INFO] [stderr]   Downloaded futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded tokio-net v0.2.0-alpha.5
[INFO] [stderr]   Downloaded prost-derive v0.5.0
[INFO] [stderr]   Downloaded grpcio-sys v0.5.4
[INFO] [stderr]   Downloaded tokio-io v0.2.0-alpha.5
[INFO] [stderr]   Downloaded rusty-p4-proto v0.1.0-alpha.1
[INFO] [stderr]   Downloaded tokio-codec v0.2.0-alpha.5
[INFO] [stderr]   Downloaded tokio-sync v0.2.0-alpha.5
[INFO] [stderr]   Downloaded tokio-executor v0.2.0-alpha.5
[INFO] [stderr]   Downloaded grpcio v0.5.4
[INFO] [stderr]   Downloaded tokio v0.2.0-alpha.5
[INFO] [stderr]   Downloaded tokio-macros v0.2.0-alpha.5
[INFO] [stderr]   Downloaded futures01 v0.1.31
[INFO] [stderr]   Downloaded pin-project v0.4.0-alpha.11
[INFO] [stderr]   Downloaded tokio-timer v0.3.0-alpha.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e8237b3efda61548666be0bbd752bc9ff1fec60e95da484de0f0bdcbe65d5c7c
[INFO] running `Command { std: "docker" "start" "-a" "e8237b3efda61548666be0bbd752bc9ff1fec60e95da484de0f0bdcbe65d5c7c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e8237b3efda61548666be0bbd752bc9ff1fec60e95da484de0f0bdcbe65d5c7c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8237b3efda61548666be0bbd752bc9ff1fec60e95da484de0f0bdcbe65d5c7c", kill_on_drop: false }`
[INFO] [stdout] e8237b3efda61548666be0bbd752bc9ff1fec60e95da484de0f0bdcbe65d5c7c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.76.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 31df78c457a2577e5678a88b666dae380f26e12cc99908515f0bde7f55c38a4c
[INFO] running `Command { std: "docker" "start" "-a" "31df78c457a2577e5678a88b666dae380f26e12cc99908515f0bde7f55c38a4c", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling memchr v2.7.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling either v1.10.0
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling proc-macro-hack v0.5.20+deprecated
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking futures v0.1.31
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling anyhow v1.0.79
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling glob v0.3.1
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling clang-sys v0.28.1
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling backtrace v0.3.69
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking byteorder v1.5.0
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling aho-corasick v1.1.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling unicode-xid v0.2.4
[INFO] [stderr]    Compiling rustix v0.38.31
[INFO] [stderr]    Compiling protobuf v2.28.0
[INFO] [stderr]    Compiling regex-syntax v0.8.2
[INFO] [stderr]    Compiling pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling which v3.1.1
[INFO] [stderr]    Compiling bindgen v0.51.1
[INFO] [stderr]    Compiling bitflags v2.4.2
[INFO] [stderr]    Compiling bytes v0.5.6
[INFO] [stderr]    Compiling linux-raw-sys v0.4.13
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling gimli v0.28.1
[INFO] [stderr]    Compiling regex-automata v0.4.5
[INFO] [stderr]    Compiling synstructure v0.12.6
[INFO] [stderr]    Compiling libz-sys v1.1.15
[INFO] [stderr]    Compiling miniz_oxide v0.7.2
[INFO] [stderr]    Compiling addr2line v0.21.0
[INFO] [stderr]    Compiling cexpr v0.3.6
[INFO] [stderr]     Checking tracing-core v0.1.32
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling prost-build v0.6.1
[INFO] [stderr]    Compiling regex v1.10.3
[INFO] [stderr]    Compiling prost-derive v0.6.1
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling object v0.32.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `async_await` has been stable since `1.39.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling tracing-attributes v0.1.27
[INFO] [stderr]    Compiling rustc-demangle v0.1.23
[INFO] [stdout] error: aborting due to 1 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 `futures-util-preview` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "31df78c457a2577e5678a88b666dae380f26e12cc99908515f0bde7f55c38a4c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31df78c457a2577e5678a88b666dae380f26e12cc99908515f0bde7f55c38a4c", kill_on_drop: false }`
[INFO] [stdout] 31df78c457a2577e5678a88b666dae380f26e12cc99908515f0bde7f55c38a4c
[INFO] documenting rusty-p4-0.1.0-alpha.2 against beta-2024-02-10 for beta-1.77-rustdoc-1
[INFO] extracting crate rusty-p4 0.1.0-alpha.2 into /workspace/builds/worker-0-tc2/source
[INFO] validating manifest of crates.io crate rusty-p4 0.1.0-alpha.2 on toolchain beta-2024-02-10
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2024-02-10" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rusty-p4 0.1.0-alpha.2
[INFO] finished tweaking crates.io crate rusty-p4 0.1.0-alpha.2
[INFO] tweaked toml for crates.io crate rusty-p4 0.1.0-alpha.2 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2024-02-10" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2024-02-10" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2024-02-10" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d6ec113f56be1940b07e77230d293639a0936fa9e67a070082998edd9dbb4221
[INFO] running `Command { std: "docker" "start" "-a" "d6ec113f56be1940b07e77230d293639a0936fa9e67a070082998edd9dbb4221", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d6ec113f56be1940b07e77230d293639a0936fa9e67a070082998edd9dbb4221", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d6ec113f56be1940b07e77230d293639a0936fa9e67a070082998edd9dbb4221", kill_on_drop: false }`
[INFO] [stdout] d6ec113f56be1940b07e77230d293639a0936fa9e67a070082998edd9dbb4221
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2024-02-10" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b947c0b76878f0b522dd596a7ed07c6a89845ca191df53a69251b7cfd06adc38
[INFO] running `Command { std: "docker" "start" "-a" "b947c0b76878f0b522dd596a7ed07c6a89845ca191df53a69251b7cfd06adc38", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro2 v1.0.78
[INFO] [stderr]    Compiling memchr v2.7.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling either v1.10.0
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling proc-macro-hack v0.5.20+deprecated
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling anyhow v1.0.79
[INFO] [stderr]     Checking futures v0.1.31
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling proc-macro-nested v0.1.7
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]    Compiling glob v0.3.1
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling clang-sys v0.28.1
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling backtrace v0.3.69
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]     Checking scopeguard v1.2.0
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking byteorder v1.5.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling aho-corasick v1.1.2
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling pin-project-internal v0.4.0-alpha.11
[INFO] [stderr]    Compiling protobuf v2.28.0
[INFO] [stderr]    Compiling unicode-xid v0.2.4
[INFO] [stderr]    Compiling regex-syntax v0.8.2
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling rustix v0.38.31
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling which v3.1.1
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling hashbrown v0.12.3
[INFO] [stderr]    Compiling gimli v0.28.1
[INFO] [stderr]    Compiling bytes v0.5.6
[INFO] [stderr]    Compiling bindgen v0.51.1
[INFO] [stderr]    Compiling synstructure v0.12.6
[INFO] [stderr]    Compiling bitflags v2.4.2
[INFO] [stderr]    Compiling regex-automata v0.4.5
[INFO] [stderr]    Compiling linux-raw-sys v0.4.13
[INFO] [stderr]     Checking tracing-core v0.1.32
[INFO] [stderr]    Compiling addr2line v0.21.0
[INFO] [stderr]    Compiling libz-sys v1.1.15
[INFO] [stderr]    Compiling cexpr v0.3.6
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling miniz_oxide v0.7.2
[INFO] [stderr]    Compiling prost-build v0.6.1
[INFO] [stderr]    Compiling regex v1.10.3
[INFO] [stderr]    Compiling prost-derive v0.6.1
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/futures-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `async_await` has been stable since `1.39.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling object v0.32.2
[INFO] [stderr]    Compiling tracing-attributes v0.1.27
[INFO] [stderr]    Compiling rustc-demangle v0.1.23
[INFO] [stdout] error: aborting due to 1 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 `futures-util-preview` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "b947c0b76878f0b522dd596a7ed07c6a89845ca191df53a69251b7cfd06adc38", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b947c0b76878f0b522dd596a7ed07c6a89845ca191df53a69251b7cfd06adc38", kill_on_drop: false }`
[INFO] [stdout] b947c0b76878f0b522dd596a7ed07c6a89845ca191df53a69251b7cfd06adc38
