[INFO] cloning repository https://github.com/slayzz/rust-grep
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/slayzz/rust-grep" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslayzz%2Frust-grep", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslayzz%2Frust-grep'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 756d084a32235ef05067a06708484eae551f050a
[INFO] checking slayzz/rust-grep against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fslayzz%2Frust-grep" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/slayzz/rust-grep on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/slayzz/rust-grep
[INFO] finished tweaking git repo https://github.com/slayzz/rust-grep
[INFO] tweaked toml for git repo https://github.com/slayzz/rust-grep written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/slayzz/rust-grep 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" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded libc v0.2.48
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4ca4311d1746e88c15b0f3db2ad8de72a7d8458725d747d835ca5a872b5cbb8a
[INFO] running `Command { std: "docker" "start" "-a" "4ca4311d1746e88c15b0f3db2ad8de72a7d8458725d747d835ca5a872b5cbb8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4ca4311d1746e88c15b0f3db2ad8de72a7d8458725d747d835ca5a872b5cbb8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ca4311d1746e88c15b0f3db2ad8de72a7d8458725d747d835ca5a872b5cbb8a", kill_on_drop: false }`
[INFO] [stdout] 4ca4311d1746e88c15b0f3db2ad8de72a7d8458725d747d835ca5a872b5cbb8a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fcb57245663be396892dcaadde374ba876f0cf3615c27d4fcb15e19adea46f0f
[INFO] running `Command { std: "docker" "start" "-a" "fcb57245663be396892dcaadde374ba876f0cf3615c27d4fcb15e19adea46f0f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.48
[INFO] [stderr]    Compiling memchr v2.1.3
[INFO] [stderr]     Checking cfg-if v0.1.6
[INFO] [stderr]     Checking lazy_static v1.2.0
[INFO] [stderr]    Compiling regex v1.1.0
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]     Checking utf8-ranges v1.0.2
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking regex-syntax v0.6.5
[INFO] [stderr]     Checking aho-corasick v0.6.9
[INFO] [stderr]     Checking command_line v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function `invalid_error` is never used
[INFO] [stdout]   --> src/utils/mod.rs:11:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub fn invalid_error(value: &str) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `print_error` is never used
[INFO] [stdout]   --> src/utils/mod.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub fn print_error(text: &str) {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `arguments` is never read
[INFO] [stdout]   --> src/parser/mod.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 36 | pub struct Config {
[INFO] [stdout]    |            ------ field in this struct
[INFO] [stdout] 37 |     pub arguments: HashSet<char>,
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Config` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `invalid_error` is never used
[INFO] [stdout]   --> src/utils/mod.rs:11:8
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub fn invalid_error(value: &str) {
[INFO] [stdout]    |        ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `print_error` is never used
[INFO] [stdout]   --> src/utils/mod.rs:15:8
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub fn print_error(text: &str) {
[INFO] [stdout]    |        ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `arguments` is never read
[INFO] [stdout]   --> src/parser/mod.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 36 | pub struct Config {
[INFO] [stdout]    |            ------ field in this struct
[INFO] [stdout] 37 |     pub arguments: HashSet<char>,
[INFO] [stdout]    |         ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Config` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/utils/mod.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     stderr().write(format!("{}\n", HELP_TEXT).as_bytes());
[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)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let _ = stderr().write(format!("{}\n", HELP_TEXT).as_bytes());
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/utils/mod.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 |     stderr().write(format!("{}\n", HELP_TEXT).as_bytes());
[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)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let _ = stderr().write(format!("{}\n", HELP_TEXT).as_bytes());
[INFO] [stdout]   |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/utils/mod.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     stderr().write(text.as_bytes());
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let _ = stderr().write(text.as_bytes());
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/utils/mod.rs:16:5
[INFO] [stdout]    |
[INFO] [stdout] 16 |     stderr().write(text.as_bytes());
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 16 |     let _ = stderr().write(text.as_bytes());
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.35s
[INFO] running `Command { std: "docker" "inspect" "fcb57245663be396892dcaadde374ba876f0cf3615c27d4fcb15e19adea46f0f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fcb57245663be396892dcaadde374ba876f0cf3615c27d4fcb15e19adea46f0f", kill_on_drop: false }`
[INFO] [stdout] fcb57245663be396892dcaadde374ba876f0cf3615c27d4fcb15e19adea46f0f