[INFO] fetching crate gob 0.1.0...
[INFO] testing gob-0.1.0 against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] extracting crate gob 0.1.0 into /workspace/builds/worker-55/source
[INFO] validating manifest of crates.io crate gob 0.1.0 on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate gob 0.1.0
[INFO] finished tweaking crates.io crate gob 0.1.0
[INFO] tweaked toml for crates.io crate gob 0.1.0 written to /workspace/builds/worker-55/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "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" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--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-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a6d9415d0ac6284032bab20aed0770bc1457234ca06d22e9d26dd3344036159c
[INFO] running `Command { std: "docker" "start" "-a" "a6d9415d0ac6284032bab20aed0770bc1457234ca06d22e9d26dd3344036159c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a6d9415d0ac6284032bab20aed0770bc1457234ca06d22e9d26dd3344036159c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a6d9415d0ac6284032bab20aed0770bc1457234ca06d22e9d26dd3344036159c", kill_on_drop: false }`
[INFO] [stdout] a6d9415d0ac6284032bab20aed0770bc1457234ca06d22e9d26dd3344036159c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-55/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c0fcbc70815b17e2cb5751392adf30119a5e24ee8d2821789219ae86f4d8710d
[INFO] running `Command { std: "docker" "start" "-a" "c0fcbc70815b17e2cb5751392adf30119a5e24ee8d2821789219ae86f4d8710d", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.32
[INFO] [stderr]    Compiling libc v0.2.108
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.81
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling safemem v0.3.3
[INFO] [stderr]    Compiling proc-macro2 v0.3.8
[INFO] [stderr]    Compiling owning_ref v0.3.3
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling syn v0.13.11
[INFO] [stderr]    Compiling quote v1.0.10
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling serde_derive_internals v0.23.1
[INFO] [stderr]    Compiling serde_schema_derive v0.0.1
[INFO] [stderr]    Compiling serde_schema v0.0.1
[INFO] [stderr]    Compiling gob v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: unnecessary braces around block return value
[INFO] [stdout]   --> src/internal/types/struct_type.rs:85:9
[INFO] [stdout]    |
[INFO] [stdout] 85 |         { Type::build().seq_type(None, TypeId::FIELD_TYPE) };
[INFO] [stdout]    |         ^^                                                ^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:9
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(warnings)]
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(unused_braces)]` implied by `#[deny(warnings)]`
[INFO] [stdout] help: remove these braces
[INFO] [stdout]    |
[INFO] [stdout] 85 -         { Type::build().seq_type(None, TypeId::FIELD_TYPE) };
[INFO] [stdout] 85 +         Type::build().seq_type(None, TypeId::FIELD_TYPE);
[INFO] [stdout]    | 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: use of deprecated associated function `std::error::Error::description`: use the Display impl or to_string()
[INFO] [stdout]   --> src/error.rs:41:58
[INFO] [stdout]    |
[INFO] [stdout] 41 |                 write!(f, "{}: {}", ::std::error::Error::description(self), msg)
[INFO] [stdout]    |                                                          ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:1:9
[INFO] [stdout]    |
[INFO] [stdout] 1  | #![deny(warnings)]
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(deprecated)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: variable does not need to be mutable
[INFO] [stdout]    --> src/internal/ser/serialize_wire_types.rs:110:29
[INFO] [stdout]     |
[INFO] [stdout] 110 |                         let mut ser = FieldValueSerializer {
[INFO] [stdout]     |                             ----^^^
[INFO] [stdout]     |                             |
[INFO] [stdout]     |                             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]    --> src/lib.rs:1:9
[INFO] [stdout]     |
[INFO] [stdout] 1   | #![deny(warnings)]
[INFO] [stdout]     |         ^^^^^^^^
[INFO] [stdout]     = note: `#[deny(unused_mut)]` implied by `#[deny(warnings)]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `gob` due to 4 previous errors
[INFO] running `Command { std: "docker" "inspect" "c0fcbc70815b17e2cb5751392adf30119a5e24ee8d2821789219ae86f4d8710d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c0fcbc70815b17e2cb5751392adf30119a5e24ee8d2821789219ae86f4d8710d", kill_on_drop: false }`
[INFO] [stdout] c0fcbc70815b17e2cb5751392adf30119a5e24ee8d2821789219ae86f4d8710d