[INFO] fetching crate guided_digraph 0.1.1...
[INFO] checking guided_digraph-0.1.1 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate guided_digraph 0.1.1 into /workspace/builds/worker-1-tc2/source
[INFO] started tweaking crates.io crate guided_digraph 0.1.1
[INFO] finished tweaking crates.io crate guided_digraph 0.1.1
[INFO] tweaked toml for crates.io crate guided_digraph 0.1.1 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate guided_digraph 0.1.1 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 guided_digraph 0.1.1 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-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 48d991304a5e01520e74e490faa6580ead70f20a3ff24a572784fe7f289e45ae
[INFO] running `Command { std: "docker" "start" "-a" "48d991304a5e01520e74e490faa6580ead70f20a3ff24a572784fe7f289e45ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "48d991304a5e01520e74e490faa6580ead70f20a3ff24a572784fe7f289e45ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "48d991304a5e01520e74e490faa6580ead70f20a3ff24a572784fe7f289e45ae", kill_on_drop: false }`
[INFO] [stdout] 48d991304a5e01520e74e490faa6580ead70f20a3ff24a572784fe7f289e45ae
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 5d83872e658001c9729a9f80677bda93540800359302ad0c777bf1b87c1f22c1
[INFO] running `Command { std: "docker" "start" "-a" "5d83872e658001c9729a9f80677bda93540800359302ad0c777bf1b87c1f22c1", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.43
[INFO] [stderr]    Compiling libc v0.2.132
[INFO] [stderr]    Compiling syn v1.0.100
[INFO] [stderr]    Compiling serde_derive v1.0.144
[INFO] [stderr]    Compiling unicode-segmentation v1.10.0
[INFO] [stderr]     Checking unicode-width v0.1.10
[INFO] [stderr]    Compiling serde v1.0.144
[INFO] [stderr]    Compiling serde_json v1.0.85
[INFO] [stderr]     Checking num_threads v0.1.6
[INFO] [stderr]    Compiling time-macros v0.2.4
[INFO] [stderr]     Checking disjoint-sets v0.4.2
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]     Checking getrandom v0.2.7
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking time v0.3.14
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]     Checking structopt v0.3.26
[INFO] [stderr]     Checking guided_digraph v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]   --> src/util.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |         format!("Could not append newline to file: {:?} -- {}", &path, err);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 66 |         let _ = format!("Could not append newline to file: {:?} -- {}", &path, err);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/run_example.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | /     #[structopt(help = "Path to example without file extension \
[INFO] [stdout] 15 | |         (e.g. 'examples/handwritten/2')")]
[INFO] [stdout] 16 | |     basename: String,
[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 `guided_digraph` (bin "run_example" test) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused return value of `must_use` that must be used
[INFO] [stdout]   --> src/util.rs:66:9
[INFO] [stdout]    |
[INFO] [stdout] 66 |         format!("Could not append newline to file: {:?} -- {}", &path, err);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 66 |         let _ = format!("Could not append newline to file: {:?} -- {}", &path, err);
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/run_example.rs:14:5
[INFO] [stdout]    |
[INFO] [stdout] 14 | /     #[structopt(help = "Path to example without file extension \
[INFO] [stdout] 15 | |         (e.g. 'examples/handwritten/2')")]
[INFO] [stdout] 16 | |     basename: String,
[INFO] [stdout]    | |____________________^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/run_compare.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     #[structopt(help = "Path to example without file extension \
[INFO] [stdout] 16 | |                         (e.g. 'examples/handwritten/2')")]
[INFO] [stdout] 17 | |     basename: String,
[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 `guided_digraph` (bin "run_example") due to 1 previous error
[INFO] [stderr] error: could not compile `guided_digraph` (bin "run_compare" test) due to 1 previous error
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/bin/run_compare.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 | /     #[structopt(help = "Path to example without file extension \
[INFO] [stdout] 16 | |                         (e.g. 'examples/handwritten/2')")]
[INFO] [stdout] 17 | |     basename: String,
[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 `guided_digraph` (bin "run_compare") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "5d83872e658001c9729a9f80677bda93540800359302ad0c777bf1b87c1f22c1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5d83872e658001c9729a9f80677bda93540800359302ad0c777bf1b87c1f22c1", kill_on_drop: false }`
[INFO] [stdout] 5d83872e658001c9729a9f80677bda93540800359302ad0c777bf1b87c1f22c1