[INFO] fetching crate mutf8 0.4.1...
[INFO] checking mutf8-0.4.1 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] extracting crate mutf8 0.4.1 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate mutf8 0.4.1 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mutf8 0.4.1
[INFO] finished tweaking crates.io crate mutf8 0.4.1
[INFO] tweaked toml for crates.io crate mutf8 0.4.1 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 179b6208465b0146ad2ed95ded0c3aa3172c926794766da6f223c0d728744c1b
[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" "179b6208465b0146ad2ed95ded0c3aa3172c926794766da6f223c0d728744c1b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "179b6208465b0146ad2ed95ded0c3aa3172c926794766da6f223c0d728744c1b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "179b6208465b0146ad2ed95ded0c3aa3172c926794766da6f223c0d728744c1b", kill_on_drop: false }`
[INFO] [stdout] 179b6208465b0146ad2ed95ded0c3aa3172c926794766da6f223c0d728744c1b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d36c4cc37b27bd192e6714e4266500e14aef35e3aa798ac93ebea29c8d00beac
[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" "d36c4cc37b27bd192e6714e4266500e14aef35e3aa798ac93ebea29c8d00beac", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.116
[INFO] [stderr]     Checking mutf8 v0.4.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/mutf8.rs:72:12
[INFO] [stdout]    |
[INFO] [stdout] 72 |             bits += ((byte4 as u32) & 0x3F);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/str.rs:194:16
[INFO] [stdout]     |
[INFO] [stdout] 194 |                 let data = unsafe { MString::from_mutf8(data) };
[INFO] [stdout]     |                            ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/str.rs:346:3
[INFO] [stdout]     |
[INFO] [stdout] 346 |         unsafe { MString::from_mutf8(&self.bytes) }
[INFO] [stdout]     |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking serde_json v1.0.58
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/mutf8.rs:72:12
[INFO] [stdout]    |
[INFO] [stdout] 72 |             bits += ((byte4 as u32) & 0x3F);
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `mutf8::mutf8_to_utf8`
[INFO] [stdout]  --> tests/to_mutf8.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use mutf8::mutf8_to_utf8;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/str.rs:194:16
[INFO] [stdout]     |
[INFO] [stdout] 194 |                 let data = unsafe { MString::from_mutf8(data) };
[INFO] [stdout]     |                            ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_unsafe)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary `unsafe` block
[INFO] [stdout]    --> src/str.rs:346:3
[INFO] [stdout]     |
[INFO] [stdout] 346 |         unsafe { MString::from_mutf8(&self.bytes) }
[INFO] [stdout]     |         ^^^^^^ unnecessary `unsafe` block
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 11.54s
[INFO] running `Command { std: "docker" "inspect" "d36c4cc37b27bd192e6714e4266500e14aef35e3aa798ac93ebea29c8d00beac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d36c4cc37b27bd192e6714e4266500e14aef35e3aa798ac93ebea29c8d00beac", kill_on_drop: false }`
[INFO] [stdout] d36c4cc37b27bd192e6714e4266500e14aef35e3aa798ac93ebea29c8d00beac