[INFO] cloning repository https://github.com/Snektron/mamba
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Snektron/mamba" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSnektron%2Fmamba", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSnektron%2Fmamba'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 8e16034b3ed9bcf9a5a92b15d9ce65d3bcf8360e
[INFO] checking Snektron/mamba against master#f90b06d7fb00470177516c5881bcec0432cb4f24 for pr-94063
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSnektron%2Fmamba" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Snektron/mamba on toolchain f90b06d7fb00470177516c5881bcec0432cb4f24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f90b06d7fb00470177516c5881bcec0432cb4f24" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Snektron/mamba
[INFO] finished tweaking git repo https://github.com/Snektron/mamba
[INFO] tweaked toml for git repo https://github.com/Snektron/mamba written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f90b06d7fb00470177516c5881bcec0432cb4f24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f90b06d7fb00470177516c5881bcec0432cb4f24" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+f90b06d7fb00470177516c5881bcec0432cb4f24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c80844b0dc7542a395dc129f570206210b22198ba497cf2dbc78f695b090ea6a
[INFO] running `Command { std: "docker" "start" "-a" "c80844b0dc7542a395dc129f570206210b22198ba497cf2dbc78f695b090ea6a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c80844b0dc7542a395dc129f570206210b22198ba497cf2dbc78f695b090ea6a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c80844b0dc7542a395dc129f570206210b22198ba497cf2dbc78f695b090ea6a", kill_on_drop: false }`
[INFO] [stdout] c80844b0dc7542a395dc129f570206210b22198ba497cf2dbc78f695b090ea6a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+f90b06d7fb00470177516c5881bcec0432cb4f24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f707dc1f696a915686b5875c9cb28a4b643f3a923863c41a886a185be3220b40
[INFO] running `Command { std: "docker" "start" "-a" "f707dc1f696a915686b5875c9cb28a4b643f3a923863c41a886a185be3220b40", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling libc v0.2.118
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling serde_derive v1.0.136
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling string_cache_shared v0.3.0
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling strsim v0.10.0
[INFO] [stderr]    Compiling bit-vec v0.6.3
[INFO] [stderr]    Compiling ordermap v0.3.5
[INFO] [stderr]    Compiling fixedbitset v0.1.9
[INFO] [stderr]    Compiling term v0.4.6
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling lalrpop-util v0.16.3
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]     Checking unicode-width v0.1.9
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking bitflags v1.3.2
[INFO] [stderr]     Checking ansi_term v0.12.1
[INFO] [stderr]     Checking vec_map v0.8.2
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling typenum v1.15.0
[INFO] [stderr]    Compiling block-padding v0.1.5
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]    Compiling bit-set v0.5.2
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling autocfg v0.1.8
[INFO] [stderr]    Compiling generic-array v0.12.4
[INFO] [stderr]    Compiling ascii-canvas v1.0.0
[INFO] [stderr]    Compiling petgraph v0.4.13
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling ena v0.11.0
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling sha2 v0.8.2
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling quote v1.0.15
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]     Checking clap v2.34.0
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling string_cache_codegen v0.4.4
[INFO] [stderr]    Compiling string_cache v0.7.5
[INFO] [stderr]    Compiling docopt v1.1.1
[INFO] [stderr]    Compiling lalrpop v0.16.3
[INFO] [stderr]    Compiling mamba v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1861:5
[INFO] [stdout]      |
[INFO] [stdout] 1861 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1861 -     (__0)
[INFO] [stdout] 1861 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1934:5
[INFO] [stdout]      |
[INFO] [stdout] 1934 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1934 -     (__0)
[INFO] [stdout] 1934 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1947:5
[INFO] [stdout]      |
[INFO] [stdout] 1947 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1947 -     (__0)
[INFO] [stdout] 1947 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1995:5
[INFO] [stdout]      |
[INFO] [stdout] 1995 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1995 -     (__0)
[INFO] [stdout] 1995 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:2009:5
[INFO] [stdout]      |
[INFO] [stdout] 2009 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 2009 -     (__0)
[INFO] [stdout] 2009 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:2216:5
[INFO] [stdout]      |
[INFO] [stdout] 2216 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 2216 -     (__0)
[INFO] [stdout] 2216 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1861:5
[INFO] [stdout]      |
[INFO] [stdout] 1861 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1861 -     (__0)
[INFO] [stdout] 1861 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1934:5
[INFO] [stdout]      |
[INFO] [stdout] 1934 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1934 -     (__0)
[INFO] [stdout] 1934 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1947:5
[INFO] [stdout]      |
[INFO] [stdout] 1947 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1947 -     (__0)
[INFO] [stdout] 1947 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:1995:5
[INFO] [stdout]      |
[INFO] [stdout] 1995 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 1995 -     (__0)
[INFO] [stdout] 1995 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:2009:5
[INFO] [stdout]      |
[INFO] [stdout] 2009 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 2009 -     (__0)
[INFO] [stdout] 2009 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/mamba-7ddd763da341873a/out/parser/grammar.rs:2216:5
[INFO] [stdout]      |
[INFO] [stdout] 2216 |     (__0)
[INFO] [stdout]      |     ^   ^
[INFO] [stdout]      |
[INFO] [stdout] help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout] 2216 -     (__0)
[INFO] [stdout] 2216 +     __0
[INFO] [stdout]      | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ast/construct.rs:188:13
[INFO] [stdout]     |
[INFO] [stdout] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[INFO] [stdout]     |             ----^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/ast/construct.rs:188:13
[INFO] [stdout]     |
[INFO] [stdout] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[INFO] [stdout]     |             ----^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2m 06s
[INFO] running `Command { std: "docker" "inspect" "f707dc1f696a915686b5875c9cb28a4b643f3a923863c41a886a185be3220b40", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f707dc1f696a915686b5875c9cb28a4b643f3a923863c41a886a185be3220b40", kill_on_drop: false }`
[INFO] [stdout] f707dc1f696a915686b5875c9cb28a4b643f3a923863c41a886a185be3220b40