[INFO] updating cached repository https://github.com/Snektron/mamba
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 8e16034b3ed9bcf9a5a92b15d9ce65d3bcf8360e
[INFO] checking Snektron/mamba against master#73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de for pr-68325
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSnektron%2Fmamba" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Snektron/mamba on toolchain 73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-6/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/workspace/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+73f76b74efcaf21bd5424d87c66cd6ed7fe5c7de" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] eeb2e7bbfbce8e832a434e13fcb4f878bc4283a9111a57b2526760e10da8e933
[INFO] running `"docker" "start" "-a" "eeb2e7bbfbce8e832a434e13fcb4f878bc4283a9111a57b2526760e10da8e933"`
[INFO] [stderr]    Compiling typenum v1.11.2
[INFO] [stderr]    Compiling ena v0.11.0
[INFO] [stderr]    Compiling docopt v1.1.0
[INFO] [stderr]    Compiling string_cache v0.7.5
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling sha2 v0.8.1
[INFO] [stderr]    Compiling lalrpop v0.16.3
[INFO] [stderr]    Compiling mamba v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1861:5
[INFO] [stderr]      |
[INFO] [stderr] 1861 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr]      |
[INFO] [stderr]      = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1934:5
[INFO] [stderr]      |
[INFO] [stderr] 1934 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1947:5
[INFO] [stderr]      |
[INFO] [stderr] 1947 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1995:5
[INFO] [stderr]      |
[INFO] [stderr] 1995 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:2009:5
[INFO] [stderr]      |
[INFO] [stderr] 2009 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:2216:5
[INFO] [stderr]      |
[INFO] [stderr] 2216 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1861:5
[INFO] [stderr]      |
[INFO] [stderr] 1861 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr]      |
[INFO] [stderr]      = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1934:5
[INFO] [stderr]      |
[INFO] [stderr] 1934 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1947:5
[INFO] [stderr]      |
[INFO] [stderr] 1947 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:1995:5
[INFO] [stderr]      |
[INFO] [stderr] 1995 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:2009:5
[INFO] [stderr]      |
[INFO] [stderr] 2009 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around block return value
[INFO] [stderr]     --> /opt/rustwide/target/debug/build/mamba-3b3068cc23c94f75/out/parser/grammar.rs:2216:5
[INFO] [stderr]      |
[INFO] [stderr] 2216 |     (__0)
[INFO] [stderr]      |     ^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/ast/construct.rs:188:13
[INFO] [stderr]     |
[INFO] [stderr] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[INFO] [stderr]     |             ----^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/ast/construct.rs:188:13
[INFO] [stderr]     |
[INFO] [stderr] 188 |         let mut t = check_arms(&from, arms, &states, &alphabet)?;
[INFO] [stderr]     |             ----^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1m 08s
[INFO] running `"docker" "inspect" "eeb2e7bbfbce8e832a434e13fcb4f878bc4283a9111a57b2526760e10da8e933"`
[INFO] running `"docker" "rm" "-f" "eeb2e7bbfbce8e832a434e13fcb4f878bc4283a9111a57b2526760e10da8e933"`
[INFO] [stdout] eeb2e7bbfbce8e832a434e13fcb4f878bc4283a9111a57b2526760e10da8e933