[INFO] fetching crate tacoda_grrs 0.1.3...
[INFO] checking tacoda_grrs-0.1.3 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate tacoda_grrs 0.1.3 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate tacoda_grrs 0.1.3
[INFO] finished tweaking crates.io crate tacoda_grrs 0.1.3
[INFO] tweaked toml for crates.io crate tacoda_grrs 0.1.3 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate tacoda_grrs 0.1.3 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 tacoda_grrs 0.1.3 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-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] 2fd93ea37029d8e18ba0f94a83d6635ca4489c7a2b422984e0ad1ee6b688d69a
[INFO] running `Command { std: "docker" "start" "-a" "2fd93ea37029d8e18ba0f94a83d6635ca4489c7a2b422984e0ad1ee6b688d69a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2fd93ea37029d8e18ba0f94a83d6635ca4489c7a2b422984e0ad1ee6b688d69a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2fd93ea37029d8e18ba0f94a83d6635ca4489c7a2b422984e0ad1ee6b688d69a", kill_on_drop: false }`
[INFO] [stdout] 2fd93ea37029d8e18ba0f94a83d6635ca4489c7a2b422984e0ad1ee6b688d69a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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] e48de1b7babc59751b40601d6965215757b8ba026248401ccfacfa11cfb0045f
[INFO] running `Command { std: "docker" "start" "-a" "e48de1b7babc59751b40601d6965215757b8ba026248401ccfacfa11cfb0045f", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling cc v1.0.37
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]     Checking lazy_static v1.3.0
[INFO] [stderr]    Compiling ryu v0.2.8
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling serde v1.0.92
[INFO] [stderr]    Compiling backtrace v0.3.30
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]     Checking ucd-util v0.1.3
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]     Checking regex-syntax v0.6.7
[INFO] [stderr]     Checking aho-corasick v0.7.3
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling unicode-segmentation v1.3.0
[INFO] [stderr]     Checking utf8-ranges v1.0.3
[INFO] [stderr]     Checking rustc-demangle v0.1.15
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking atty v0.2.11
[INFO] [stderr]     Checking log v0.4.6
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking normalize-line-endings v0.2.2
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking float-cmp v0.4.0
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking predicates v1.0.1
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]    Compiling structopt-derive v0.2.16
[INFO] [stderr]     Checking structopt v0.2.16
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]     Checking exitfailure v0.5.1
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stderr]     Checking tacoda_grrs v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:12:13
[INFO] [stdout]    |
[INFO] [stdout] 12 |             writeln!(writer, "{}", 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] 12 |             let _ = writeln!(writer, "{}", line);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/lib.rs:12:13
[INFO] [stdout]    |
[INFO] [stdout] 12 |             writeln!(writer, "{}", 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] 12 |             let _ = writeln!(writer, "{}", line);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `self`
[INFO] [stdout]  --> tests/cli.rs:5:15
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::io::{self, Write};
[INFO] [stdout]   |               ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]  --> tests/cli.rs:8:42
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn file_doesnt_exist() -> Result<(), Box<std::error::Error>> {
[INFO] [stdout]   |                                          ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]   = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]   = note: `#[warn(bare_trait_objects)]` (part of `#[warn(rust_2021_compatibility)]`) on by default
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn file_doesnt_exist() -> Result<(), Box<dyn std::error::Error>> {
[INFO] [stdout]   |                                          +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> tests/cli.rs:20:45
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn find_content_in_file() -> Result<(), Box<std::error::Error>> {
[INFO] [stdout]    |                                             ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout] help: if this is a dyn-compatible trait, use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn find_content_in_file() -> Result<(), Box<dyn std::error::Error>> {
[INFO] [stdout]    |                                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/main.rs:6:10
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(StructOpt)]
[INFO] [stdout]   |          ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]   = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]  --> src/main.rs:6:10
[INFO] [stdout]   |
[INFO] [stdout] 6 | #[derive(StructOpt)]
[INFO] [stdout]   |          ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout]   = note: this error originates in the derive macro `StructOpt` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tacoda_grrs` (bin "tacoda_grrs" test) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `tacoda_grrs` (bin "tacoda_grrs") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "e48de1b7babc59751b40601d6965215757b8ba026248401ccfacfa11cfb0045f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e48de1b7babc59751b40601d6965215757b8ba026248401ccfacfa11cfb0045f", kill_on_drop: false }`
[INFO] [stdout] e48de1b7babc59751b40601d6965215757b8ba026248401ccfacfa11cfb0045f
