[INFO] fetching crate float_fast_print 0.1.2...
[INFO] checking float_fast_print-0.1.2 against try#05c8870159e4f328578a970e125aa76d24f03b56 for pr-76219
[INFO] extracting crate float_fast_print 0.1.2 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate float_fast_print 0.1.2 on toolchain 05c8870159e4f328578a970e125aa76d24f03b56
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate float_fast_print 0.1.2
[INFO] finished tweaking crates.io crate float_fast_print 0.1.2
[INFO] tweaked toml for crates.io crate float_fast_print 0.1.2 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+05c8870159e4f328578a970e125aa76d24f03b56" "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] 2e7e889c41957336789f8a3c77954d439be702993de85bb088abd6ce36052066
[INFO] running `Command { std: "docker" "start" "-a" "2e7e889c41957336789f8a3c77954d439be702993de85bb088abd6ce36052066", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e7e889c41957336789f8a3c77954d439be702993de85bb088abd6ce36052066", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e7e889c41957336789f8a3c77954d439be702993de85bb088abd6ce36052066", kill_on_drop: false }`
[INFO] [stdout] 2e7e889c41957336789f8a3c77954d439be702993de85bb088abd6ce36052066
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+05c8870159e4f328578a970e125aa76d24f03b56" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 34f17aef968235649668d9cf49b0a426d1c11a261eba552b1c35d82051f10ded
[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" "34f17aef968235649668d9cf49b0a426d1c11a261eba552b1c35d82051f10ded", kill_on_drop: false }`
[INFO] [stderr]     Checking float_fast_print v0.1.2 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stdout] warning: unused `std::result::Result` that must be used
[INFO] [stdout]   --> tests/benchmarks.rs:17:9
[INFO] [stdout]    |
[INFO] [stdout] 17 |         write!(&mut buffer, "{:?}", x);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[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: unused `std::result::Result` that must be used
[INFO] [stdout]   --> tests/benchmarks.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |         write!(&mut buffer, "{}", x);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[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: unused `std::result::Result` that must be used
[INFO] [stdout]   --> tests/benchmarks.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         write!(&mut buffer, "{:?}", x);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[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: unused `std::result::Result` that must be used
[INFO] [stdout]   --> tests/benchmarks.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |         write!(&mut buffer, "{}", x);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[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: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.63s
[INFO] running `Command { std: "docker" "inspect" "34f17aef968235649668d9cf49b0a426d1c11a261eba552b1c35d82051f10ded", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34f17aef968235649668d9cf49b0a426d1c11a261eba552b1c35d82051f10ded", kill_on_drop: false }`
[INFO] [stdout] 34f17aef968235649668d9cf49b0a426d1c11a261eba552b1c35d82051f10ded