[INFO] cloning repository https://github.com/JesterOrNot/MathLang
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/JesterOrNot/MathLang" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJesterOrNot%2FMathLang", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJesterOrNot%2FMathLang'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7edd069884e3bfa03c8e9ebc96a30af752c60ff6
[INFO] checking JesterOrNot/MathLang/7edd069884e3bfa03c8e9ebc96a30af752c60ff6 against master#ab869e094a907cc5d19b4080f22eccaf347f1f95 for pr-129604
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJesterOrNot%2FMathLang" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/JesterOrNot/MathLang on toolchain ab869e094a907cc5d19b4080f22eccaf347f1f95
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/JesterOrNot/MathLang
[INFO] finished tweaking git repo https://github.com/JesterOrNot/MathLang
[INFO] tweaked toml for git repo https://github.com/JesterOrNot/MathLang written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/JesterOrNot/MathLang 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" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded structopt v0.3.7
[INFO] [stderr]   Downloaded utf8-ranges v1.0.4
[INFO] [stderr]   Downloaded structopt-derive v0.4.0
[INFO] [stderr]   Downloaded rustversion v1.0.1
[INFO] [stderr]   Downloaded ucd-util v0.1.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ecf86986f42806ea087d8300283d49b050828409d1a77645f7e2d921ac4196d6
[INFO] running `Command { std: "docker" "start" "-a" "ecf86986f42806ea087d8300283d49b050828409d1a77645f7e2d921ac4196d6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ecf86986f42806ea087d8300283d49b050828409d1a77645f7e2d921ac4196d6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ecf86986f42806ea087d8300283d49b050828409d1a77645f7e2d921ac4196d6", kill_on_drop: false }`
[INFO] [stdout] ecf86986f42806ea087d8300283d49b050828409d1a77645f7e2d921ac4196d6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+ab869e094a907cc5d19b4080f22eccaf347f1f95" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 863db5a6bf1066545fa12de68c3cd03a69b27baeb115ab55c8b832edb6c4278a
[INFO] running `Command { std: "docker" "start" "-a" "863db5a6bf1066545fa12de68c3cd03a69b27baeb115ab55c8b832edb6c4278a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling libc v0.2.66
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]     Checking unicode-width v0.1.7
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]     Checking ucd-util v0.1.5
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]     Checking vec_map v0.8.1
[INFO] [stderr]     Checking utf8-ranges v1.0.4
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking regex-syntax v0.5.6
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]     Checking aho-corasick v0.6.10
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling syn-mid v0.4.0
[INFO] [stderr]    Compiling rustversion v1.0.1
[INFO] [stderr]    Compiling proc-macro-error v0.4.4
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.3
[INFO] [stderr]    Compiling structopt-derive v0.4.0
[INFO] [stderr]     Checking structopt v0.3.7
[INFO] [stderr]     Checking mathlang v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/main.rs:93:13
[INFO] [stdout]    |
[INFO] [stdout] 93 |             &line.push_str("   ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 93 |             let _ = &line.push_str("   ");
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/main.rs:93:13
[INFO] [stdout]    |
[INFO] [stdout] 93 |             &line.push_str("   ");
[INFO] [stdout]    |             ^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 93 |             let _ = &line.push_str("   ");
[INFO] [stdout]    |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 12.95s
[INFO] running `Command { std: "docker" "inspect" "863db5a6bf1066545fa12de68c3cd03a69b27baeb115ab55c8b832edb6c4278a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "863db5a6bf1066545fa12de68c3cd03a69b27baeb115ab55c8b832edb6c4278a", kill_on_drop: false }`
[INFO] [stdout] 863db5a6bf1066545fa12de68c3cd03a69b27baeb115ab55c8b832edb6c4278a