[INFO] fetching crate nop-json 2.0.5...
[INFO] checking nop-json-2.0.5 against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] extracting crate nop-json 2.0.5 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate nop-json 2.0.5 on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nop-json 2.0.5
[INFO] finished tweaking crates.io crate nop-json 2.0.5
[INFO] tweaked toml for crates.io crate nop-json 2.0.5 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8bbc545edfcf34a23ab9137e17d6ca1d0a3ac06d98147e47c773a7675e7b63f7
[INFO] running `Command { std: "docker" "start" "-a" "8bbc545edfcf34a23ab9137e17d6ca1d0a3ac06d98147e47c773a7675e7b63f7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8bbc545edfcf34a23ab9137e17d6ca1d0a3ac06d98147e47c773a7675e7b63f7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bbc545edfcf34a23ab9137e17d6ca1d0a3ac06d98147e47c773a7675e7b63f7", kill_on_drop: false }`
[INFO] [stdout] 8bbc545edfcf34a23ab9137e17d6ca1d0a3ac06d98147e47c773a7675e7b63f7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] da3e8d1614c5eb5052ba6d49911fdf853f39a7367f4b7c6fd820b1464ce371e8
[INFO] running `Command { std: "docker" "start" "-a" "da3e8d1614c5eb5052ba6d49911fdf853f39a7367f4b7c6fd820b1464ce371e8", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.32
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]     Checking numtoa v0.2.4
[INFO] [stderr]     Checking read_iter v0.1.2
[INFO] [stderr]    Compiling quote v1.0.10
[INFO] [stderr]    Compiling syn v1.0.82
[INFO] [stderr]    Compiling nop-json-derive v2.0.5
[INFO] [stderr]     Checking nop-json v2.0.5 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]     --> src/nop_json.rs:1169:4
[INFO] [stdout]      |
[INFO] [stdout] 1169 |             &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] 1169 |             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:1184:4
[INFO] [stdout]      |
[INFO] [stdout] 1184 |             &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] 1184 |             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:1200:4
[INFO] [stdout]      |
[INFO] [stdout] 1200 |             &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] 1200 |             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:2035:6
[INFO] [stdout]      |
[INFO] [stdout] 2035 |             {    &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] 2035 |             {    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:2039:6
[INFO] [stdout]      |
[INFO] [stdout] 2039 |             {    &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] 2039 |             {    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:2043:6
[INFO] [stdout]      |
[INFO] [stdout] 2043 |             {    &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] 2043 |             {    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:1169:4
[INFO] [stdout]      |
[INFO] [stdout] 1169 |             &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] 1169 |             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:1184:4
[INFO] [stdout]      |
[INFO] [stdout] 1184 |             &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] 1184 |             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:1200:4
[INFO] [stdout]      |
[INFO] [stdout] 1200 |             &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] 1200 |             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:2035:6
[INFO] [stdout]      |
[INFO] [stdout] 2035 |             {    &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] 2035 |             {    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:2039:6
[INFO] [stdout]      |
[INFO] [stdout] 2039 |             {    &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] 2039 |             {    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:2043:6
[INFO] [stdout]      |
[INFO] [stdout] 2043 |             {    &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] 2043 |             {    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 11.91s
[INFO] running `Command { std: "docker" "inspect" "da3e8d1614c5eb5052ba6d49911fdf853f39a7367f4b7c6fd820b1464ce371e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "da3e8d1614c5eb5052ba6d49911fdf853f39a7367f4b7c6fd820b1464ce371e8", kill_on_drop: false }`
[INFO] [stdout] da3e8d1614c5eb5052ba6d49911fdf853f39a7367f4b7c6fd820b1464ce371e8