[INFO] fetching crate rust_json_parser 1.0.1...
[INFO] testing rust_json_parser-1.0.1 against master#c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38 for pr-146098-8
[INFO] extracting crate rust_json_parser 1.0.1 into /workspace/builds/worker-7-tc1/source
[INFO] started tweaking crates.io crate rust_json_parser 1.0.1
[INFO] finished tweaking crates.io crate rust_json_parser 1.0.1
[INFO] tweaked toml for crates.io crate rust_json_parser 1.0.1 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate rust_json_parser 1.0.1 on toolchain c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "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" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 11 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "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-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 94e35af02da22a400e59e2a2c70a690fc07dbb67c0ed989b345b5e1ecad05d35
[INFO] running `Command { std: "docker" "start" "-a" "94e35af02da22a400e59e2a2c70a690fc07dbb67c0ed989b345b5e1ecad05d35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "94e35af02da22a400e59e2a2c70a690fc07dbb67c0ed989b345b5e1ecad05d35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "94e35af02da22a400e59e2a2c70a690fc07dbb67c0ed989b345b5e1ecad05d35", kill_on_drop: false }`
[INFO] [stdout] 94e35af02da22a400e59e2a2c70a690fc07dbb67c0ed989b345b5e1ecad05d35
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8be4370136c8ac11a2bceeedddc4e740b2f16d89ecf34d191d636d23990d0127
[INFO] running `Command { std: "docker" "start" "-a" "8be4370136c8ac11a2bceeedddc4e740b2f16d89ecf34d191d636d23990d0127", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde_core v1.0.228
[INFO] [stderr]    Compiling serde_json v1.0.145
[INFO] [stderr]    Compiling rust_json_parser v1.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Value`
[INFO] [stdout]  --> src/lib.rs:1:39
[INFO] [stdout]   |
[INFO] [stdout] 1 | use serde_json::{from_str, to_string, Value};
[INFO] [stdout]   |                                       ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this function depends on never type fallback being `()`
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn parse_json_string(json_str: &str) -> Result<String, String> {
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in Rust 2024 and in a future release in all editions!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2024/never-type-fallback.html>
[INFO] [stdout]   = help: specify the types explicitly
[INFO] [stdout] note: in edition 2024, the requirement `!: serde_core::ser::Serialize` will fail
[INFO] [stdout]  --> src/lib.rs:8:28
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let result = to_string(&parsed_json).map_err(|e| format!("Failed to serialize JSON: {}", e))?;
[INFO] [stdout]   |                            ^^^^^^^^^^^^
[INFO] [stdout]   = note: `#[deny(dependency_on_unit_never_type_fallback)]` (part of `#[deny(rust_2024_compatibility)]`) on by default
[INFO] [stdout] help: use `()` annotations to avoid fallback changes
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let parsed_json: () = from_str(json_str).map_err(|e| format!("Failed to parse JSON: {}", e))?;
[INFO] [stdout]   |                    ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_json_parser` (lib) due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "8be4370136c8ac11a2bceeedddc4e740b2f16d89ecf34d191d636d23990d0127", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8be4370136c8ac11a2bceeedddc4e740b2f16d89ecf34d191d636d23990d0127", kill_on_drop: false }`
[INFO] [stdout] 8be4370136c8ac11a2bceeedddc4e740b2f16d89ecf34d191d636d23990d0127