[INFO] fetching crate tokenlock 0.3.8...
[INFO] checking tokenlock-0.3.8 against try#c659ee110de67e82444e4b6c8407c1a9af9c2cf6 for pr-145608-1
[INFO] extracting crate tokenlock 0.3.8 into /workspace/builds/worker-4-tc2/source
[INFO] removed /workspace/builds/worker-4-tc2/source/rust-toolchain
[INFO] started tweaking crates.io crate tokenlock 0.3.8
[INFO] finished tweaking crates.io crate tokenlock 0.3.8
[INFO] tweaked toml for crates.io crate tokenlock 0.3.8 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate tokenlock 0.3.8 on toolchain c659ee110de67e82444e4b6c8407c1a9af9c2cf6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "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" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 83 packages to latest compatible versions
[INFO] [stderr]       Adding async-scoped v0.7.1 (available: v0.9.0)
[INFO] [stderr]       Adding env_logger v0.9.3 (available: v0.11.8)
[INFO] [stderr]       Adding spin v0.9.8 (available: v0.10.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 507af5ccb5000ca52d56573ee3bf36b0fcf89dbb17ac7f78c060ceda8c532c08
[INFO] running `Command { std: "docker" "start" "-a" "507af5ccb5000ca52d56573ee3bf36b0fcf89dbb17ac7f78c060ceda8c532c08", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "507af5ccb5000ca52d56573ee3bf36b0fcf89dbb17ac7f78c060ceda8c532c08", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "507af5ccb5000ca52d56573ee3bf36b0fcf89dbb17ac7f78c060ceda8c532c08", kill_on_drop: false }`
[INFO] [stdout] 507af5ccb5000ca52d56573ee3bf36b0fcf89dbb17ac7f78c060ceda8c532c08
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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@sha256:7ad1b28ee6f5f7f699f6cf7015098d6ccdd96d6f2d78dd06228f5b4c9faf309c" "/opt/rustwide/cargo-home/bin/cargo" "+c659ee110de67e82444e4b6c8407c1a9af9c2cf6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a94c8d69d1a5f1eb44264e2d46eee75f64e7b8b79b0c99b33fdac0c9048333d4
[INFO] running `Command { std: "docker" "start" "-a" "a94c8d69d1a5f1eb44264e2d46eee75f64e7b8b79b0c99b33fdac0c9048333d4", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling tokenlock v0.3.8 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking humantime v2.2.0
[INFO] [stderr]     Checking env_logger v0.9.3
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:346:13
[INFO] [stdout]     |
[INFO] [stdout] 346 |         all(compiler_has_cfg_target_has_atomic, target_has_atomic = "ptr"),
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: expected names are: `docsrs`, `feature`, and `test` and 31 more
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout]     = note: `#[warn(unexpected_cfgs)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:347:13
[INFO] [stdout]     |
[INFO] [stdout] 347 |         not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:358:13
[INFO] [stdout]     |
[INFO] [stdout] 358 |         all(compiler_has_cfg_target_has_atomic, target_has_atomic = "ptr"),
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:359:13
[INFO] [stdout]     |
[INFO] [stdout] 359 |         not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     all(compiler_has_cfg_target_has_atomic, target_has_atomic = "8"),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:91:9
[INFO] [stdout]    |
[INFO] [stdout] 91 |     all(compiler_has_cfg_target_has_atomic, target_has_atomic = "8"),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:92:9
[INFO] [stdout]    |
[INFO] [stdout] 92 |     not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]    --> src/singleton.rs:133:31
[INFO] [stdout]     |
[INFO] [stdout] 133 | struct Invariant<Tag: ?Sized>(fn(&Tag) -> &Tag);
[INFO] [stdout]     |        ---------              ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |        |
[INFO] [stdout]     |        field in this struct
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider removing this field
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling futures-macro v0.3.31
[INFO] [stderr]    Compiling pin-project-internal v1.1.10
[INFO] [stderr]    Compiling tokio-macros v2.5.0
[INFO] [stderr]     Checking tokio v1.47.1
[INFO] [stderr]     Checking futures-util v0.3.31
[INFO] [stderr]     Checking pin-project v1.1.10
[INFO] [stderr]     Checking futures-executor v0.3.31
[INFO] [stderr]     Checking futures v0.3.31
[INFO] [stderr]     Checking async-scoped v0.7.1
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:346:13
[INFO] [stdout]     |
[INFO] [stdout] 346 |         all(compiler_has_cfg_target_has_atomic, target_has_atomic = "ptr"),
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: expected names are: `docsrs`, `feature`, and `test` and 31 more
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout]     = note: `#[warn(unexpected_cfgs)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:347:13
[INFO] [stdout]     |
[INFO] [stdout] 347 |         not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:358:13
[INFO] [stdout]     |
[INFO] [stdout] 358 |         all(compiler_has_cfg_target_has_atomic, target_has_atomic = "ptr"),
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]    --> src/lib.rs:359:13
[INFO] [stdout]     |
[INFO] [stdout] 359 |         not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     all(compiler_has_cfg_target_has_atomic, target_has_atomic = "8"),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:51:9
[INFO] [stdout]    |
[INFO] [stdout] 51 |     not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:91:9
[INFO] [stdout]    |
[INFO] [stdout] 91 |     all(compiler_has_cfg_target_has_atomic, target_has_atomic = "8"),
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `compiler_has_cfg_target_has_atomic`
[INFO] [stdout]   --> src/singleton_factory.rs:92:9
[INFO] [stdout]    |
[INFO] [stdout] 92 |     not(compiler_has_cfg_target_has_atomic)
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider using a Cargo feature instead
[INFO] [stdout]    = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]             [lints.rust]
[INFO] [stdout]             unexpected_cfgs = { level = "warn", check-cfg = ['cfg(compiler_has_cfg_target_has_atomic)'] }
[INFO] [stdout]    = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(compiler_has_cfg_target_has_atomic)");` to the top of the `build.rs`
[INFO] [stdout]    = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]    --> src/singleton.rs:133:31
[INFO] [stdout]     |
[INFO] [stdout] 133 | struct Invariant<Tag: ?Sized>(fn(&Tag) -> &Tag);
[INFO] [stdout]     |        ---------              ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |        |
[INFO] [stdout]     |        field in this struct
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider removing this field
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.69s
[INFO] running `Command { std: "docker" "inspect" "a94c8d69d1a5f1eb44264e2d46eee75f64e7b8b79b0c99b33fdac0c9048333d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a94c8d69d1a5f1eb44264e2d46eee75f64e7b8b79b0c99b33fdac0c9048333d4", kill_on_drop: false }`
[INFO] [stdout] a94c8d69d1a5f1eb44264e2d46eee75f64e7b8b79b0c99b33fdac0c9048333d4