[INFO] fetching crate cli-grep 0.1.2...
[INFO] checking cli-grep-0.1.2 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate cli-grep 0.1.2 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate cli-grep 0.1.2
[INFO] finished tweaking crates.io crate cli-grep 0.1.2
[INFO] tweaked toml for crates.io crate cli-grep 0.1.2 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate cli-grep 0.1.2 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 cli-grep 0.1.2 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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 7b774dd7684b6d993b6209952a092e4a0907e7338c80ea802332fd2ce979ca06
[INFO] running `Command { std: "docker" "start" "-a" "7b774dd7684b6d993b6209952a092e4a0907e7338c80ea802332fd2ce979ca06", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7b774dd7684b6d993b6209952a092e4a0907e7338c80ea802332fd2ce979ca06", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b774dd7684b6d993b6209952a092e4a0907e7338c80ea802332fd2ce979ca06", kill_on_drop: false }`
[INFO] [stdout] 7b774dd7684b6d993b6209952a092e4a0907e7338c80ea802332fd2ce979ca06
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 3137ec006ab004ea661d1f27305492c4ad13182b80e229cc3fc1504353cd937c
[INFO] running `Command { std: "docker" "start" "-a" "3137ec006ab004ea661d1f27305492c4ad13182b80e229cc3fc1504353cd937c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]    Compiling cc v1.0.47
[INFO] [stderr]    Compiling failure_derive v0.1.6
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling num-traits v0.2.10
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]     Checking quick-error v1.2.2
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking number_prefix v0.3.0
[INFO] [stderr]     Checking termcolor v1.0.5
[INFO] [stderr]     Checking humantime v1.3.0
[INFO] [stderr]    Compiling escargot v0.3.1
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking normalize-line-endings v0.2.2
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking float-cmp v0.5.3
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking clicolors-control v1.0.1
[INFO] [stderr]     Checking termios v0.3.1
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking backtrace v0.3.40
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking console v0.9.1
[INFO] [stderr]     Checking env_logger v0.7.1
[INFO] [stderr]     Checking predicates v1.0.2
[INFO] [stderr]     Checking indicatif v0.13.0
[INFO] [stderr]    Compiling synstructure v0.12.3
[INFO] [stderr]    Compiling proc-macro-error v0.2.6
[INFO] [stderr]    Compiling serde_derive v1.0.102
[INFO] [stderr]    Compiling structopt-derive v0.3.5
[INFO] [stderr]     Checking failure v0.1.6
[INFO] [stderr]     Checking structopt v0.3.5
[INFO] [stderr]     Checking exitfailure v0.5.1
[INFO] [stderr]     Checking cli-grep v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/lib.rs:4:13
[INFO] [stdout]   |
[INFO] [stdout] 4 |             writeln!(writter, "{}", line);
[INFO] [stdout]   |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[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] 4 |             let _ = writeln!(writter, "{}", line);
[INFO] [stdout]   |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `cli-grep` (bin "cli-grep") due to 1 previous error
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/cli-grep.rs:8:5
[INFO] [stdout]   |
[INFO] [stdout] 8 |     pattern: 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] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "3137ec006ab004ea661d1f27305492c4ad13182b80e229cc3fc1504353cd937c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3137ec006ab004ea661d1f27305492c4ad13182b80e229cc3fc1504353cd937c", kill_on_drop: false }`
[INFO] [stdout] 3137ec006ab004ea661d1f27305492c4ad13182b80e229cc3fc1504353cd937c
