[INFO] cloning repository https://github.com/jjc914/cis198-homework4
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jjc914/cis198-homework4" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjjc914%2Fcis198-homework4", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjjc914%2Fcis198-homework4'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 04298b1987809c5c19fce090bab12f612a298dea
[INFO] checking jjc914/cis198-homework4 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjjc914%2Fcis198-homework4" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/jjc914/cis198-homework4
[INFO] finished tweaking git repo https://github.com/jjc914/cis198-homework4
[INFO] tweaked toml for git repo https://github.com/jjc914/cis198-homework4 written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/jjc914/cis198-homework4 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 git repo https://github.com/jjc914/cis198-homework4 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] 09540b0557ae1eb7c1fdfccabdcfaaa9d1b563ce3b2d33fa36083fb9b1f5b25e
[INFO] running `Command { std: "docker" "start" "-a" "09540b0557ae1eb7c1fdfccabdcfaaa9d1b563ce3b2d33fa36083fb9b1f5b25e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "09540b0557ae1eb7c1fdfccabdcfaaa9d1b563ce3b2d33fa36083fb9b1f5b25e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "09540b0557ae1eb7c1fdfccabdcfaaa9d1b563ce3b2d33fa36083fb9b1f5b25e", kill_on_drop: false }`
[INFO] [stdout] 09540b0557ae1eb7c1fdfccabdcfaaa9d1b563ce3b2d33fa36083fb9b1f5b25e
[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] 0ce28bb1458ee51f9a88aef100abe207eace710e8b14187f3cd7ae7ad0c794a0
[INFO] running `Command { std: "docker" "start" "-a" "0ce28bb1458ee51f9a88aef100abe207eace710e8b14187f3cd7ae7ad0c794a0", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.76
[INFO] [stderr]    Compiling libc v0.2.152
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]     Checking unicode-width v0.1.11
[INFO] [stderr]    Compiling unicode-segmentation v1.10.1
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking nix v0.20.2
[INFO] [stderr]     Checking clap v2.34.0
[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 strace v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `syscalls_to_trace`
[INFO] [stdout]   --> src/main.rs:60:5
[INFO] [stdout]    |
[INFO] [stdout] 60 |     syscalls_to_trace: &HashSet<&str>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_syscalls_to_trace`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `options`
[INFO] [stdout]   --> src/main.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let options = util::ptrace_set_options(child_pid);
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_options`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `pid`
[INFO] [stdout]   --> src/main.rs:70:32
[INFO] [stdout]    |
[INFO] [stdout] 70 |             WaitStatus::Exited(pid, _) => {
[INFO] [stdout]    |                                ^^^ help: if this is intentional, prefix it with an underscore: `_pid`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:30:13
[INFO] [stdout]    |
[INFO] [stdout] 30 |             run_tracer(child, &syscalls);
[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] 30 |             let _ = run_tracer(child, &syscalls);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:33:13
[INFO] [stdout]    |
[INFO] [stdout] 33 |             run_tracee(opt.exe, opt.exe_args);
[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] 33 |             let _ = run_tracee(opt.exe, opt.exe_args);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |     ptrace::cont(child_pid, None);
[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] 65 |     let _ = ptrace::cont(child_pid, None);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | /     #[structopt(short = "t", long = "to_trace")]
[INFO] [stdout] 25 | |     pub to_trace: Vec<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/args.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | /     #[structopt(short = "d", long = "dont_trace", conflicts_with = "to_trace")]
[INFO] [stdout] 28 | |     pub dont_trace: Vec<String>,
[INFO] [stdout]    | |_______________________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:30:5
[INFO] [stdout]    |
[INFO] [stdout] 30 |     pub exe: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:31:5
[INFO] [stdout]    |
[INFO] [stdout] 31 |     pub exe_args: Vec<String>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `strace` (bin "strace") due to 4 previous errors; 6 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused variable: `syscalls_to_trace`
[INFO] [stdout]   --> src/main.rs:60:5
[INFO] [stdout]    |
[INFO] [stdout] 60 |     syscalls_to_trace: &HashSet<&str>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_syscalls_to_trace`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `options`
[INFO] [stdout]   --> src/main.rs:64:9
[INFO] [stdout]    |
[INFO] [stdout] 64 |     let options = util::ptrace_set_options(child_pid);
[INFO] [stdout]    |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_options`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `pid`
[INFO] [stdout]   --> src/main.rs:70:32
[INFO] [stdout]    |
[INFO] [stdout] 70 |             WaitStatus::Exited(pid, _) => {
[INFO] [stdout]    |                                ^^^ help: if this is intentional, prefix it with an underscore: `_pid`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:30:13
[INFO] [stdout]    |
[INFO] [stdout] 30 |             run_tracer(child, &syscalls);
[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] 30 |             let _ = run_tracer(child, &syscalls);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:33:13
[INFO] [stdout]    |
[INFO] [stdout] 33 |             run_tracee(opt.exe, opt.exe_args);
[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] 33 |             let _ = run_tracee(opt.exe, opt.exe_args);
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/main.rs:65:5
[INFO] [stdout]    |
[INFO] [stdout] 65 |     ptrace::cont(child_pid, None);
[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] 65 |     let _ = ptrace::cont(child_pid, None);
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:24:5
[INFO] [stdout]    |
[INFO] [stdout] 24 | /     #[structopt(short = "t", long = "to_trace")]
[INFO] [stdout] 25 | |     pub to_trace: Vec<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/args.rs:27:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | /     #[structopt(short = "d", long = "dont_trace", conflicts_with = "to_trace")]
[INFO] [stdout] 28 | |     pub dont_trace: Vec<String>,
[INFO] [stdout]    | |_______________________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:30:5
[INFO] [stdout]    |
[INFO] [stdout] 30 |     pub exe: String,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<String, Infallible>
[INFO] [stdout]   --> src/args.rs:31:5
[INFO] [stdout]    |
[INFO] [stdout] 31 |     pub exe_args: Vec<String>,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `strace` (bin "strace" test) due to 4 previous errors; 6 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "0ce28bb1458ee51f9a88aef100abe207eace710e8b14187f3cd7ae7ad0c794a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0ce28bb1458ee51f9a88aef100abe207eace710e8b14187f3cd7ae7ad0c794a0", kill_on_drop: false }`
[INFO] [stdout] 0ce28bb1458ee51f9a88aef100abe207eace710e8b14187f3cd7ae7ad0c794a0