[INFO] fetching crate free-algebra 0.1.0...
[INFO] checking free-algebra-0.1.0 against try#1c5262aa6c045a581fb974488793f09ed51fc498 for pr-78376
[INFO] extracting crate free-algebra 0.1.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate free-algebra 0.1.0 on toolchain 1c5262aa6c045a581fb974488793f09ed51fc498
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1c5262aa6c045a581fb974488793f09ed51fc498" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate free-algebra 0.1.0
[INFO] finished tweaking crates.io crate free-algebra 0.1.0
[INFO] tweaked toml for crates.io crate free-algebra 0.1.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1c5262aa6c045a581fb974488793f09ed51fc498" "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" "+1c5262aa6c045a581fb974488793f09ed51fc498" "fetch" "--locked" "--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-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+1c5262aa6c045a581fb974488793f09ed51fc498" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7f9f757702c68e4a2fd795bfb090588736e5d858a5823cd9020937481bfac0a0
[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" "7f9f757702c68e4a2fd795bfb090588736e5d858a5823cd9020937481bfac0a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7f9f757702c68e4a2fd795bfb090588736e5d858a5823cd9020937481bfac0a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7f9f757702c68e4a2fd795bfb090588736e5d858a5823cd9020937481bfac0a0", kill_on_drop: false }`
[INFO] [stdout] 7f9f757702c68e4a2fd795bfb090588736e5d858a5823cd9020937481bfac0a0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+1c5262aa6c045a581fb974488793f09ed51fc498" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e2f9d29ca2f504c69aef05986996dedc4453e0b0506065c3a1d7bef293ba1a99
[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" "e2f9d29ca2f504c69aef05986996dedc4453e0b0506065c3a1d7bef293ba1a99", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking maths-traits v0.2.1
[INFO] [stderr]    Compiling derivative v1.0.4
[INFO] [stderr]     Checking free-algebra v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:77:12
[INFO] [stdout]    |
[INFO] [stdout] 77 | #![feature(specialization)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:77:12
[INFO] [stdout]    |
[INFO] [stdout] 77 | #![feature(specialization)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 25.13s
[INFO] running `Command { std: "docker" "inspect" "e2f9d29ca2f504c69aef05986996dedc4453e0b0506065c3a1d7bef293ba1a99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2f9d29ca2f504c69aef05986996dedc4453e0b0506065c3a1d7bef293ba1a99", kill_on_drop: false }`
[INFO] [stdout] e2f9d29ca2f504c69aef05986996dedc4453e0b0506065c3a1d7bef293ba1a99