[INFO] fetching crate one_billion_rows_challenge 0.1.0...
[INFO] checking one_billion_rows_challenge-0.1.0 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate one_billion_rows_challenge 0.1.0 into /workspace/builds/worker-5-tc2/source
[INFO] started tweaking crates.io crate one_billion_rows_challenge 0.1.0
[INFO] finished tweaking crates.io crate one_billion_rows_challenge 0.1.0
[INFO] tweaked toml for crates.io crate one_billion_rows_challenge 0.1.0 written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate one_billion_rows_challenge 0.1.0 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate one_billion_rows_challenge 0.1.0 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 42a28ffd95b27d471118498cc9c108fe6048f0c9d6a69dcffba8f368a0656507
[INFO] running `Command { std: "docker" "start" "-a" "42a28ffd95b27d471118498cc9c108fe6048f0c9d6a69dcffba8f368a0656507", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "42a28ffd95b27d471118498cc9c108fe6048f0c9d6a69dcffba8f368a0656507", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42a28ffd95b27d471118498cc9c108fe6048f0c9d6a69dcffba8f368a0656507", kill_on_drop: false }`
[INFO] [stdout] 42a28ffd95b27d471118498cc9c108fe6048f0c9d6a69dcffba8f368a0656507
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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 -Dunmustuse_in_always_ok" "-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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9570be80f95482f6c2b835f829c9830a83eb8af2456bdeae50ba9f6b84f1fa27
[INFO] running `Command { std: "docker" "start" "-a" "9570be80f95482f6c2b835f829c9830a83eb8af2456bdeae50ba9f6b84f1fa27", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.152
[INFO] [stderr]     Checking either v1.9.0
[INFO] [stderr]     Checking itertools v0.12.0
[INFO] [stderr]     Checking memmap2 v0.9.3
[INFO] [stderr]     Checking one_billion_rows_challenge v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:169:13
[INFO] [stdout]     |
[INFO] [stdout] 169 |     if cfg!(debug) {
[INFO] [stdout]     |             ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: expected names are: `docsrs`, `feature`, and `test` and 31 more
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout]     = note: `#[warn(unexpected_cfgs)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:194:17
[INFO] [stdout]     |
[INFO] [stdout] 194 |         if cfg!(debug) {
[INFO] [stdout]     |                 ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |     if cfg!(debug) {
[INFO] [stdout]     |             ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]    --> src/main.rs:207:19
[INFO] [stdout]     |
[INFO] [stdout] 207 |     let mut res = String::from_str("{").unwrap_unchecked();
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `one_billion_rows_challenge` (bin "one_billion_rows_challenge") due to 1 previous error; 3 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:169:13
[INFO] [stdout]     |
[INFO] [stdout] 169 |     if cfg!(debug) {
[INFO] [stdout]     |             ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: expected names are: `docsrs`, `feature`, and `test` and 31 more
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout]     = note: `#[warn(unexpected_cfgs)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:194:17
[INFO] [stdout]     |
[INFO] [stdout] 194 |         if cfg!(debug) {
[INFO] [stdout]     |                 ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unexpected `cfg` condition name: `debug`
[INFO] [stdout]    --> src/main.rs:201:13
[INFO] [stdout]     |
[INFO] [stdout] 201 |     if cfg!(debug) {
[INFO] [stdout]     |             ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = help: consider using a Cargo feature instead
[INFO] [stdout]     = help: or consider adding in `Cargo.toml` the `check-cfg` lint config for the lint:
[INFO] [stdout]              [lints.rust]
[INFO] [stdout]              unexpected_cfgs = { level = "warn", check-cfg = ['cfg(debug)'] }
[INFO] [stdout]     = help: or consider adding `println!("cargo::rustc-check-cfg=cfg(debug)");` to the top of the `build.rs`
[INFO] [stdout]     = note: see <https://doc.rust-lang.org/nightly/rustc/check-cfg/cargo-specifics.html> for more information about checking conditional configuration
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]    --> src/main.rs:207:19
[INFO] [stdout]     |
[INFO] [stdout] 207 |     let mut res = String::from_str("{").unwrap_unchecked();
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `one_billion_rows_challenge` (bin "one_billion_rows_challenge" test) due to 1 previous error; 3 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "9570be80f95482f6c2b835f829c9830a83eb8af2456bdeae50ba9f6b84f1fa27", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9570be80f95482f6c2b835f829c9830a83eb8af2456bdeae50ba9f6b84f1fa27", kill_on_drop: false }`
[INFO] [stdout] 9570be80f95482f6c2b835f829c9830a83eb8af2456bdeae50ba9f6b84f1fa27