[INFO] fetching crate union-find 0.4.2...
[INFO] checking union-find-0.4.2 against master#ceab6128fa48a616bfd3e3adf4bc80133b8ee223 for no-never-type-fallback
[INFO] extracting crate union-find 0.4.2 into /workspace/builds/worker-1-tc1/source
[INFO] validating manifest of crates.io crate union-find 0.4.2 on toolchain ceab6128fa48a616bfd3e3adf4bc80133b8ee223
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate union-find 0.4.2
[INFO] finished tweaking crates.io crate union-find 0.4.2
[INFO] tweaked toml for crates.io crate union-find 0.4.2 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 71 packages
[INFO] [stderr]       Adding anes v0.1.6 (latest: v0.2.0)
[INFO] [stderr]       Adding itertools v0.10.5 (latest: v0.12.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1e978dbeb89aeb2ecd311bec36555513100ace85848a1b0ee46ae9eea88c8760
[INFO] running `Command { std: "docker" "start" "-a" "1e978dbeb89aeb2ecd311bec36555513100ace85848a1b0ee46ae9eea88c8760", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1e978dbeb89aeb2ecd311bec36555513100ace85848a1b0ee46ae9eea88c8760", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1e978dbeb89aeb2ecd311bec36555513100ace85848a1b0ee46ae9eea88c8760", kill_on_drop: false }`
[INFO] [stdout] 1e978dbeb89aeb2ecd311bec36555513100ace85848a1b0ee46ae9eea88c8760
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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=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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ceab6128fa48a616bfd3e3adf4bc80133b8ee223" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e46fe355e237269ffa41a50ae19cd270a6abf11c357678dec7411cea6836413a
[INFO] running `Command { std: "docker" "start" "-a" "e46fe355e237269ffa41a50ae19cd270a6abf11c357678dec7411cea6836413a", kill_on_drop: false }`
[INFO] [stderr]     Checking half v2.4.0
[INFO] [stderr]     Checking serde v1.0.197
[INFO] [stderr]     Checking union-find v0.4.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/traits.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/quick_union.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/quick_find.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking ciborium-ll v0.2.2
[INFO] [stderr]     Checking serde_json v1.0.115
[INFO] [stderr]     Checking ciborium v0.2.2
[INFO] [stderr]     Checking tinytemplate v1.2.1
[INFO] [stderr]     Checking criterion v0.5.1
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/traits.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/quick_union.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `FromIterator` is imported redundantly
[INFO] [stdout]  --> src/quick_find.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::iter::FromIterator;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:148:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `FromIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Default` is imported redundantly
[INFO] [stdout]  --> src/tests.rs:9:5
[INFO] [stdout]   |
[INFO] [stdout] 9 | use std::default::Default;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/ceab6128fa48a616bfd3e3adf4bc80133b8ee223/library/std/src/prelude/mod.rs:144:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `Default` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 3.20s
[INFO] running `Command { std: "docker" "inspect" "e46fe355e237269ffa41a50ae19cd270a6abf11c357678dec7411cea6836413a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e46fe355e237269ffa41a50ae19cd270a6abf11c357678dec7411cea6836413a", kill_on_drop: false }`
[INFO] [stdout] e46fe355e237269ffa41a50ae19cd270a6abf11c357678dec7411cea6836413a