[INFO] fetching crate lalrpop-lambda 0.6.1...
[INFO] testing lalrpop-lambda-0.6.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate lalrpop-lambda 0.6.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate lalrpop-lambda 0.6.1 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate lalrpop-lambda 0.6.1
[INFO] finished tweaking crates.io crate lalrpop-lambda 0.6.1
[INFO] tweaked toml for crates.io crate lalrpop-lambda 0.6.1 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate lalrpop-lambda 0.6.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d88edc55f7fe86489a46e8d7545383a6c56de7634cefee41237066ca73a4f18c
[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" "d88edc55f7fe86489a46e8d7545383a6c56de7634cefee41237066ca73a4f18c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d88edc55f7fe86489a46e8d7545383a6c56de7634cefee41237066ca73a4f18c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d88edc55f7fe86489a46e8d7545383a6c56de7634cefee41237066ca73a4f18c", kill_on_drop: false }`
[INFO] [stdout] d88edc55f7fe86489a46e8d7545383a6c56de7634cefee41237066ca73a4f18c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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=warn" "-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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", 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] fc92af0e71b88dcae80bdecc8fdce8d3e1aaeff6a4e4d2796721215ab4edfd1e
[INFO] running `Command { std: "docker" "start" "-a" "fc92af0e71b88dcae80bdecc8fdce8d3e1aaeff6a4e4d2796721215ab4edfd1e", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.58
[INFO] [stderr]    Compiling rand_core v0.4.0
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling syn v0.15.35
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling memchr v2.2.0
[INFO] [stderr]    Compiling typenum v1.10.0
[INFO] [stderr]    Compiling ucd-util v0.1.3
[INFO] [stderr]    Compiling serde v1.0.92
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]    Compiling utf8-ranges v1.0.3
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.45
[INFO] [stderr]    Compiling strsim v0.9.2
[INFO] [stderr]    Compiling either v1.5.2
[INFO] [stderr]    Compiling bumpalo v2.4.3
[INFO] [stderr]    Compiling opaque-debug v0.2.2
[INFO] [stderr]    Compiling new_debug_unreachable v1.0.3
[INFO] [stderr]    Compiling lalrpop-util v0.17.0
[INFO] [stderr]    Compiling diff v0.1.11
[INFO] [stderr]    Compiling wasm-bindgen v0.2.45
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling block-padding v0.1.4
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling regex-syntax v0.6.7
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]    Compiling itertools v0.8.0
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]    Compiling ena v0.13.0
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling dirs v1.0.5
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling generic-array v0.12.0
[INFO] [stderr]    Compiling term v0.5.2
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling digest v0.8.0
[INFO] [stderr]    Compiling aho-corasick v0.7.3
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling sha2 v0.8.0
[INFO] [stderr]    Compiling ascii-canvas v2.0.0
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling string_cache_codegen v0.4.2
[INFO] [stderr]    Compiling string_cache v0.7.3
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.45
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.45
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.45
[INFO] [stderr]    Compiling docopt v1.1.0
[INFO] [stderr]    Compiling lalrpop v0.17.0
[INFO] [stderr]    Compiling lalrpop-lambda v0.6.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:42:1
[INFO] [stdout]    |
[INFO] [stdout] 42 | / #![feature(non_ascii_idents,
[INFO] [stdout] 43 | |            box_syntax,
[INFO] [stdout] 44 | |            box_patterns,
[INFO] [stdout] 45 | |            fn_traits,
[INFO] [stdout] 46 | |            unboxed_closures)]
[INFO] [stdout]    | |_____________________________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: identifier pair considered confusable between `y` and `γ`
[INFO] [stdout]    --> src/macros.rs:144:14
[INFO] [stdout]     |
[INFO] [stdout] 144 | macro_rules! γ {
[INFO] [stdout]     |              ^
[INFO] [stdout]     | 
[INFO] [stdout]    ::: src/lib.rs:347:51
[INFO] [stdout]     |
[INFO] [stdout] 347 |         assert_eq!(set! { variable!(x), variable!(y) },
[INFO] [stdout]     |                                                   - this is where the previous identifier occurred
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(confusable_idents)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:2949:5
[INFO] [stdout]      |
[INFO] [stdout] 2949 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout]      |
[INFO] [stdout]      = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:2960:5
[INFO] [stdout]      |
[INFO] [stdout] 2960 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:3085:5
[INFO] [stdout]      |
[INFO] [stdout] 3085 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:3096:5
[INFO] [stdout]      |
[INFO] [stdout] 3096 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:3201:5
[INFO] [stdout]      |
[INFO] [stdout] 3201 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around block return value
[INFO] [stdout]     --> /opt/rustwide/target/debug/build/lalrpop-lambda-aba975c05ab3728e/out/parse.rs:3235:5
[INFO] [stdout]      |
[INFO] [stdout] 3235 |     (__0)
[INFO] [stdout]      |     ^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lalrpop-lambda`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "fc92af0e71b88dcae80bdecc8fdce8d3e1aaeff6a4e4d2796721215ab4edfd1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc92af0e71b88dcae80bdecc8fdce8d3e1aaeff6a4e4d2796721215ab4edfd1e", kill_on_drop: false }`
[INFO] [stdout] fc92af0e71b88dcae80bdecc8fdce8d3e1aaeff6a4e4d2796721215ab4edfd1e