[INFO] updating cached repository https://github.com/theduke/rust-serialization-benchmarks
[INFO] running `Command { std: "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", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4d24c6531d75942ef58ef4005e6dbb8f661b2225
[INFO] testing theduke/rust-serialization-benchmarks against try#03a1ea71b075ab964b5278bc6e74cd6c52c36ee0 for pr-74409
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftheduke%2Frust-serialization-benchmarks" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/theduke/rust-serialization-benchmarks on toolchain 03a1ea71b075ab964b5278bc6e74cd6c52c36ee0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/theduke/rust-serialization-benchmarks
[INFO] finished tweaking git repo https://github.com/theduke/rust-serialization-benchmarks
[INFO] tweaked toml for git repo https://github.com/theduke/rust-serialization-benchmarks written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/theduke/rust-serialization-benchmarks already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "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] 119fe0643a609f039b4ae6f6ad35c43dabfe458ca905cec246bd90d9e7ecbdba
[INFO] running `Command { std: "docker" "start" "-a" "119fe0643a609f039b4ae6f6ad35c43dabfe458ca905cec246bd90d9e7ecbdba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "119fe0643a609f039b4ae6f6ad35c43dabfe458ca905cec246bd90d9e7ecbdba", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "119fe0643a609f039b4ae6f6ad35c43dabfe458ca905cec246bd90d9e7ecbdba", kill_on_drop: false }`
[INFO] [stdout] 119fe0643a609f039b4ae6f6ad35c43dabfe458ca905cec246bd90d9e7ecbdba
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4ea699e055aa94e2e6730ea300594c6261ab2987d397ca4756d6de961d6fc7f4
[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" "4ea699e055aa94e2e6730ea300594c6261ab2987d397ca4756d6de961d6fc7f4", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.19
[INFO] [stderr]    Compiling num-traits v0.1.36
[INFO] [stderr]    Compiling serde v0.8.21
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]    Compiling winapi v0.2.8
[INFO] [stderr]    Compiling rustc-serialize v0.3.22
[INFO] [stderr]    Compiling unicode-xid v0.0.3
[INFO] [stderr]    Compiling gcc v0.3.41
[INFO] [stderr]    Compiling quote v0.3.10
[INFO] [stderr]    Compiling byteorder v0.5.3
[INFO] [stderr]    Compiling byteorder v1.0.0
[INFO] [stderr]    Compiling dtoa v0.2.2
[INFO] [stderr]    Compiling regex-syntax v0.3.9
[INFO] [stderr]    Compiling utf8-ranges v0.1.3
[INFO] [stderr]    Compiling lazy_static v0.2.2
[INFO] [stderr]    Compiling iter-read v0.1.0
[INFO] [stderr]    Compiling byteorder v0.3.13
[INFO] [stderr]    Compiling linked-hash-map v0.0.9
[INFO] [stderr]    Compiling itoa v0.1.1
[INFO] [stderr]    Compiling libc v0.1.12
[INFO] [stderr]    Compiling bencher v0.1.2 (https://github.com/theduke/bencher.git#59ee1f8f)
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]    Compiling syn v0.10.5
[INFO] [stderr]    Compiling rand v0.3.15
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling time v0.1.35
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling aho-corasick v0.5.3
[INFO] [stderr]    Compiling num-integer v0.1.32
[INFO] [stderr]    Compiling rmp v0.8.1
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stderr]    Compiling num-iter v0.1.32
[INFO] [stderr]    Compiling num v0.1.36
[INFO] [stderr]    Compiling chrono v0.2.25
[INFO] [stderr]    Compiling regex v0.1.80
[INFO] [stderr]    Compiling serde_codegen_internals v0.11.3
[INFO] [stderr]    Compiling serde_codegen v0.8.21
[INFO] [stderr]    Compiling serde_test v0.8.21
[INFO] [stderr]    Compiling rmp-serde v0.11.0
[INFO] [stderr]    Compiling serde_json v0.8.4
[INFO] [stderr]    Compiling serde_cbor v0.4.0
[INFO] [stderr]    Compiling serde_derive v0.8.21
[INFO] [stderr]    Compiling num-bigint v0.1.35
[INFO] [stderr]    Compiling cbor v0.4.0
[INFO] [stderr]    Compiling toml v0.2.1
[INFO] [stderr]    Compiling bincode v0.6.1
[INFO] [stderr]    Compiling linked-hash-map v0.3.0
[INFO] [stderr]    Compiling serde-pickle v0.2.0
[INFO] [stderr]    Compiling yaml-rust v0.3.5
[INFO] [stderr]    Compiling serde-hjson v0.8.1
[INFO] [stderr]    Compiling serde_yaml v0.5.0
[INFO] [stderr]    Compiling bson v0.3.2
[INFO] [stderr]    Compiling rust_serialization_benchmark v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `proc_macro` has been stable since 1.29.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro)]
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `step_by`
[INFO] [stdout]  --> src/main.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(step_by)]
[INFO] [stdout]   |            ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_serialization_benchmark`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4ea699e055aa94e2e6730ea300594c6261ab2987d397ca4756d6de961d6fc7f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4ea699e055aa94e2e6730ea300594c6261ab2987d397ca4756d6de961d6fc7f4", kill_on_drop: false }`
[INFO] [stdout] 4ea699e055aa94e2e6730ea300594c6261ab2987d397ca4756d6de961d6fc7f4