[INFO] cloning repository https://github.com/mr-adult/json-formatter
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mr-adult/json-formatter" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmr-adult%2Fjson-formatter", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmr-adult%2Fjson-formatter'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 304c02914e9db302aa0f33b19d6f79a66e5f10b0
[INFO] building mr-adult/json-formatter against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmr-adult%2Fjson-formatter" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mr-adult/json-formatter on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mr-adult/json-formatter
[INFO] finished tweaking git repo https://github.com/mr-adult/json-formatter
[INFO] tweaked toml for git repo https://github.com/mr-adult/json-formatter written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/mr-adult/json-formatter already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3b47e0fd9157572dc5fc581fa6d5205cb63ab30f237c22a7f4cb28ecb97a9130
[INFO] running `Command { std: "docker" "start" "-a" "3b47e0fd9157572dc5fc581fa6d5205cb63ab30f237c22a7f4cb28ecb97a9130", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3b47e0fd9157572dc5fc581fa6d5205cb63ab30f237c22a7f4cb28ecb97a9130", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3b47e0fd9157572dc5fc581fa6d5205cb63ab30f237c22a7f4cb28ecb97a9130", kill_on_drop: false }`
[INFO] [stdout] 3b47e0fd9157572dc5fc581fa6d5205cb63ab30f237c22a7f4cb28ecb97a9130
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e9f02c340f0b5f373c9f264e80f88d73a4a19b93a8dcb66512e541455e3bd130
[INFO] running `Command { std: "docker" "start" "-a" "e9f02c340f0b5f373c9f264e80f88d73a4a19b93a8dcb66512e541455e3bd130", kill_on_drop: false }`
[INFO] [stderr]    Compiling toy-json-formatter v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `cow` is never read
[INFO] [stdout]    --> src/lib.rs:217:5
[INFO] [stdout]     |
[INFO] [stdout] 215 | pub struct JsonString<'i> {
[INFO] [stdout]     |            ---------- field in this struct
[INFO] [stdout] 216 |     source: &'i str,
[INFO] [stdout] 217 |     cow: Option<Cow<'i, String>>,
[INFO] [stdout]     |     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `JsonString` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.63s
[INFO] running `Command { std: "docker" "inspect" "e9f02c340f0b5f373c9f264e80f88d73a4a19b93a8dcb66512e541455e3bd130", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e9f02c340f0b5f373c9f264e80f88d73a4a19b93a8dcb66512e541455e3bd130", kill_on_drop: false }`
[INFO] [stdout] e9f02c340f0b5f373c9f264e80f88d73a4a19b93a8dcb66512e541455e3bd130
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3de470f464853f2f4264dc28a0947e3504d85db5b07a61935f0689dd3bf7071d
[INFO] running `Command { std: "docker" "start" "-a" "3de470f464853f2f4264dc28a0947e3504d85db5b07a61935f0689dd3bf7071d", kill_on_drop: false }`
[INFO] [stdout] warning: field `cow` is never read
[INFO] [stdout]    --> src/lib.rs:217:5
[INFO] [stdout]     |
[INFO] [stdout] 215 | pub struct JsonString<'i> {
[INFO] [stdout]     |            ---------- field in this struct
[INFO] [stdout] 216 |     source: &'i str,
[INFO] [stdout] 217 |     cow: Option<Cow<'i, String>>,
[INFO] [stdout]     |     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `JsonString` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling toy-json-formatter v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `cow` is never read
[INFO] [stdout]    --> src/lib.rs:217:5
[INFO] [stdout]     |
[INFO] [stdout] 215 | pub struct JsonString<'i> {
[INFO] [stdout]     |            ---------- field in this struct
[INFO] [stdout] 216 |     source: &'i str,
[INFO] [stdout] 217 |     cow: Option<Cow<'i, String>>,
[INFO] [stdout]     |     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `JsonString` has derived impls for the traits `Debug` and `Clone`, but these are intentionally ignored during dead code analysis
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.60s
[INFO] running `Command { std: "docker" "inspect" "3de470f464853f2f4264dc28a0947e3504d85db5b07a61935f0689dd3bf7071d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3de470f464853f2f4264dc28a0947e3504d85db5b07a61935f0689dd3bf7071d", kill_on_drop: false }`
[INFO] [stdout] 3de470f464853f2f4264dc28a0947e3504d85db5b07a61935f0689dd3bf7071d