[INFO] fetching crate serde-json-helpers 0.1.2...
[INFO] checking serde-json-helpers-0.1.2 against try#c659ee110de67e82444e4b6c8407c1a9af9c2cf6 for pr-145608-1
[INFO] extracting crate serde-json-helpers 0.1.2 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate serde-json-helpers 0.1.2
[INFO] finished tweaking crates.io crate serde-json-helpers 0.1.2
[INFO] tweaked toml for crates.io crate serde-json-helpers 0.1.2 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate serde-json-helpers 0.1.2 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 14 packages to latest compatible versions
[INFO] [stderr]       Adding proc-macro2 v0.4.30 (available: v1.0.101)
[INFO] [stderr]       Adding quote v0.6.13 (available: v1.0.40)
[INFO] [stderr]       Adding syn v0.15.44 (available: v2.0.106)
[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] [stderr]     Blocking waiting for file lock on package cache
[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] 952f1b5ad834bf01682117245027dfd35fbe91fd49212187d887039f76b287e5
[INFO] running `Command { std: "docker" "start" "-a" "952f1b5ad834bf01682117245027dfd35fbe91fd49212187d887039f76b287e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "952f1b5ad834bf01682117245027dfd35fbe91fd49212187d887039f76b287e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "952f1b5ad834bf01682117245027dfd35fbe91fd49212187d887039f76b287e5", kill_on_drop: false }`
[INFO] [stdout] 952f1b5ad834bf01682117245027dfd35fbe91fd49212187d887039f76b287e5
[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] 97357c5f3e0219c6d3fe5d9010c31cdb52ed4638c239ea74d6adc31aa4942930
[INFO] running `Command { std: "docker" "start" "-a" "97357c5f3e0219c6d3fe5d9010c31cdb52ed4638c239ea74d6adc31aa4942930", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling serde v1.0.219
[INFO] [stderr]     Checking quote v0.6.13
[INFO] [stderr]     Checking serde-json-helpers v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_uppercase` that must be used
[INFO] [stdout]   --> src/string_transform.rs:99:21
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     s.to_ascii_uppercase();
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: to uppercase the value in-place, use `make_ascii_uppercase()`
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     let _ = s.to_ascii_uppercase();
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_lowercase` that must be used
[INFO] [stdout]    --> src/string_transform.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout] 115 |             s.to_ascii_lowercase();
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: to lowercase the value in-place, use `make_ascii_lowercase()`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 115 |             let _ = s.to_ascii_lowercase();
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_uppercase` that must be used
[INFO] [stdout]   --> src/string_transform.rs:99:21
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     s.to_ascii_uppercase();
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: to uppercase the value in-place, use `make_ascii_uppercase()`
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     let _ = s.to_ascii_uppercase();
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_lowercase` that must be used
[INFO] [stdout]    --> src/string_transform.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout] 115 |             s.to_ascii_lowercase();
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: to lowercase the value in-place, use `make_ascii_lowercase()`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 115 |             let _ = s.to_ascii_lowercase();
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_uppercase` that must be used
[INFO] [stdout]   --> src/string_transform.rs:99:21
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     s.to_ascii_uppercase();
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: to uppercase the value in-place, use `make_ascii_uppercase()`
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 99 |                     let _ = s.to_ascii_uppercase();
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `str::<impl str>::to_ascii_lowercase` that must be used
[INFO] [stdout]    --> src/string_transform.rs:115:13
[INFO] [stdout]     |
[INFO] [stdout] 115 |             s.to_ascii_lowercase();
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: to lowercase the value in-place, use `make_ascii_lowercase()`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 115 |             let _ = s.to_ascii_lowercase();
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 11.14s
[INFO] running `Command { std: "docker" "inspect" "97357c5f3e0219c6d3fe5d9010c31cdb52ed4638c239ea74d6adc31aa4942930", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97357c5f3e0219c6d3fe5d9010c31cdb52ed4638c239ea74d6adc31aa4942930", kill_on_drop: false }`
[INFO] [stdout] 97357c5f3e0219c6d3fe5d9010c31cdb52ed4638c239ea74d6adc31aa4942930