[INFO] cloning repository https://github.com/ElectricCoffee/word_generator
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ElectricCoffee/word_generator" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8066370286e040f0e85b5648677089f10e82d6bc
[INFO] checking ElectricCoffee/word_generator against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FElectricCoffee%2Fword_generator" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ElectricCoffee/word_generator on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ElectricCoffee/word_generator
[INFO] finished tweaking git repo https://github.com/ElectricCoffee/word_generator
[INFO] tweaked toml for git repo https://github.com/ElectricCoffee/word_generator written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/ElectricCoffee/word_generator already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 574963938b358ddb76f5091689f742717b5529768a24ed3d5225757707b586aa
[INFO] running `Command { std: "docker" "start" "-a" "574963938b358ddb76f5091689f742717b5529768a24ed3d5225757707b586aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "574963938b358ddb76f5091689f742717b5529768a24ed3d5225757707b586aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "574963938b358ddb76f5091689f742717b5529768a24ed3d5225757707b586aa", kill_on_drop: false }`
[INFO] [stdout] 574963938b358ddb76f5091689f742717b5529768a24ed3d5225757707b586aa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b2250b8dc84e718c1cf19f28228612c37094835ed203916f0fabefe0a254441a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "b2250b8dc84e718c1cf19f28228612c37094835ed203916f0fabefe0a254441a", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.42
[INFO] [stderr]     Checking rand v0.5.1
[INFO] [stderr]     Checking word_generator v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut v = vec![$($e),*];
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 72 |     let v = seq![opt!(C), C, V, opt!(C), C, V, opt!(C)]; // generates (C)CV(C)CV(C) words
[INFO] [stdout]    |             ------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout]    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:10:13
[INFO] [stdout]    |
[INFO] [stdout] 10 |         let mut v = vec![$($e),*];
[INFO] [stdout]    |             ----^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] ...
[INFO] [stdout] 72 |     let v = seq![opt!(C), C, V, opt!(C), C, V, opt!(C)]; // generates (C)CV(C)CV(C) words
[INFO] [stdout]    |             ------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout]    = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.12s
[INFO] running `Command { std: "docker" "inspect" "b2250b8dc84e718c1cf19f28228612c37094835ed203916f0fabefe0a254441a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2250b8dc84e718c1cf19f28228612c37094835ed203916f0fabefe0a254441a", kill_on_drop: false }`
[INFO] [stdout] b2250b8dc84e718c1cf19f28228612c37094835ed203916f0fabefe0a254441a