[INFO] fetching crate nop-json 2.0.4...
[INFO] checking nop-json-2.0.4 against try#39e1293fce4b650061e85dda88aa428f726a8444 for pr-88041
[INFO] extracting crate nop-json 2.0.4 into /workspace/builds/worker-29/source
[INFO] validating manifest of crates.io crate nop-json 2.0.4 on toolchain 39e1293fce4b650061e85dda88aa428f726a8444
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nop-json 2.0.4
[INFO] finished tweaking crates.io crate nop-json 2.0.4
[INFO] tweaked toml for crates.io crate nop-json 2.0.4 written to /workspace/builds/worker-29/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded nop-json-derive v2.0.4
[INFO] [stderr]   Downloaded read_iter v0.1.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-29/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-29/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7cab9d186d70bb4e9bebe3e360f14a0af8fc494be52f206685a36852f00999cc
[INFO] running `Command { std: "docker" "start" "-a" "7cab9d186d70bb4e9bebe3e360f14a0af8fc494be52f206685a36852f00999cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7cab9d186d70bb4e9bebe3e360f14a0af8fc494be52f206685a36852f00999cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7cab9d186d70bb4e9bebe3e360f14a0af8fc494be52f206685a36852f00999cc", kill_on_drop: false }`
[INFO] [stdout] 7cab9d186d70bb4e9bebe3e360f14a0af8fc494be52f206685a36852f00999cc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-29/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-29/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+39e1293fce4b650061e85dda88aa428f726a8444" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a8fc229579cd90b39f786e444ba063c86ecca7a117eebf8b9656a3a8741b4f4b
[INFO] running `Command { std: "docker" "start" "-a" "a8fc229579cd90b39f786e444ba063c86ecca7a117eebf8b9656a3a8741b4f4b", kill_on_drop: false }`
[INFO] [stderr]     Checking numtoa v0.2.4
[INFO] [stderr]     Checking read_iter v0.1.2
[INFO] [stderr]    Compiling nop-json-derive v2.0.4
[INFO] [stderr]     Checking nop-json v2.0.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1150:4
[INFO] [stdout]      |
[INFO] [stdout] 1150 |             &mut buffer[pos+len .. pos+len+e].copy_from_slice(&FORMAT_NUM_WIDTH_Z[0 .. e]);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1150 |             let _ = &mut buffer[pos+len .. pos+len+e].copy_from_slice(&FORMAT_NUM_WIDTH_Z[0 .. e]);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1165:4
[INFO] [stdout]      |
[INFO] [stdout] 1165 |             &mut buffer[pos .. pos+e-len+2].copy_from_slice(&FORMAT_NUM_WIDTH_0Z[0 .. e-len+2]);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1165 |             let _ = &mut buffer[pos .. pos+e-len+2].copy_from_slice(&FORMAT_NUM_WIDTH_0Z[0 .. e-len+2]);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1181:4
[INFO] [stdout]      |
[INFO] [stdout] 1181 |             &mut buffer[len .. len+exponent_str.len()].copy_from_slice(exponent_str);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1181 |             let _ = &mut buffer[len .. len+exponent_str.len()].copy_from_slice(exponent_str);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2022:6
[INFO] [stdout]      |
[INFO] [stdout] 2022 |             {    &mut self.buffer[0 .. 4].copy_from_slice(b"null");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2022 |             {    let _ = &mut self.buffer[0 .. 4].copy_from_slice(b"null");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2026:6
[INFO] [stdout]      |
[INFO] [stdout] 2026 |             {    &mut self.buffer[0 .. 5].copy_from_slice(b"false");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2026 |             {    let _ = &mut self.buffer[0 .. 5].copy_from_slice(b"false");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2030:6
[INFO] [stdout]      |
[INFO] [stdout] 2030 |             {    &mut self.buffer[0 .. 4].copy_from_slice(b"true");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2030 |             {    let _ = &mut self.buffer[0 .. 4].copy_from_slice(b"true");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/debug_to_json.rs:176:5
[INFO] [stdout]     |
[INFO] [stdout] 176 |                 &mut buffer[0 .. mantissa.len()].copy_from_slice(&mantissa);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 176 |                 let _ = &mut buffer[0 .. mantissa.len()].copy_from_slice(&mantissa);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1150:4
[INFO] [stdout]      |
[INFO] [stdout] 1150 |             &mut buffer[pos+len .. pos+len+e].copy_from_slice(&FORMAT_NUM_WIDTH_Z[0 .. e]);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1150 |             let _ = &mut buffer[pos+len .. pos+len+e].copy_from_slice(&FORMAT_NUM_WIDTH_Z[0 .. e]);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1165:4
[INFO] [stdout]      |
[INFO] [stdout] 1165 |             &mut buffer[pos .. pos+e-len+2].copy_from_slice(&FORMAT_NUM_WIDTH_0Z[0 .. e-len+2]);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1165 |             let _ = &mut buffer[pos .. pos+e-len+2].copy_from_slice(&FORMAT_NUM_WIDTH_0Z[0 .. e-len+2]);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1181:4
[INFO] [stdout]      |
[INFO] [stdout] 1181 |             &mut buffer[len .. len+exponent_str.len()].copy_from_slice(exponent_str);
[INFO] [stdout]      |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 1181 |             let _ = &mut buffer[len .. len+exponent_str.len()].copy_from_slice(exponent_str);
[INFO] [stdout]      |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2022:6
[INFO] [stdout]      |
[INFO] [stdout] 2022 |             {    &mut self.buffer[0 .. 4].copy_from_slice(b"null");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2022 |             {    let _ = &mut self.buffer[0 .. 4].copy_from_slice(b"null");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2026:6
[INFO] [stdout]      |
[INFO] [stdout] 2026 |             {    &mut self.buffer[0 .. 5].copy_from_slice(b"false");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2026 |             {    let _ = &mut self.buffer[0 .. 5].copy_from_slice(b"false");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:2030:6
[INFO] [stdout]      |
[INFO] [stdout] 2030 |             {    &mut self.buffer[0 .. 4].copy_from_slice(b"true");
[INFO] [stdout]      |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]      |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]      |
[INFO] [stdout] 2030 |             {    let _ = &mut self.buffer[0 .. 4].copy_from_slice(b"true");
[INFO] [stdout]      |                  +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/debug_to_json.rs:176:5
[INFO] [stdout]     |
[INFO] [stdout] 176 |                 &mut buffer[0 .. mantissa.len()].copy_from_slice(&mantissa);
[INFO] [stdout]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 176 |                 let _ = &mut buffer[0 .. mantissa.len()].copy_from_slice(&mantissa);
[INFO] [stdout]     |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.78s
[INFO] running `Command { std: "docker" "inspect" "a8fc229579cd90b39f786e444ba063c86ecca7a117eebf8b9656a3a8741b4f4b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8fc229579cd90b39f786e444ba063c86ecca7a117eebf8b9656a3a8741b4f4b", kill_on_drop: false }`
[INFO] [stdout] a8fc229579cd90b39f786e444ba063c86ecca7a117eebf8b9656a3a8741b4f4b