[INFO] fetching crate ak 0.1.1...
[INFO] checking ak-0.1.1 against master#936f2600b6c903b04387f74ed5cbce88bb06d243 for pr-91141
[INFO] extracting crate ak 0.1.1 into /workspace/builds/worker-41/source
[INFO] validating manifest of crates.io crate ak 0.1.1 on toolchain 936f2600b6c903b04387f74ed5cbce88bb06d243
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ak 0.1.1
[INFO] finished tweaking crates.io crate ak 0.1.1
[INFO] tweaked toml for crates.io crate ak 0.1.1 written to /workspace/builds/worker-41/source/Cargo.toml
[INFO] crate crates.io crate ak 0.1.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "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-41/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/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" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2f3e2971845f51d03ca5e2c5d799bde59f4dbae010cbcec3bfa5b0d72f82eeeb
[INFO] running `Command { std: "docker" "start" "-a" "2f3e2971845f51d03ca5e2c5d799bde59f4dbae010cbcec3bfa5b0d72f82eeeb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2f3e2971845f51d03ca5e2c5d799bde59f4dbae010cbcec3bfa5b0d72f82eeeb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2f3e2971845f51d03ca5e2c5d799bde59f4dbae010cbcec3bfa5b0d72f82eeeb", kill_on_drop: false }`
[INFO] [stdout] 2f3e2971845f51d03ca5e2c5d799bde59f4dbae010cbcec3bfa5b0d72f82eeeb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-41/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" "+936f2600b6c903b04387f74ed5cbce88bb06d243" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4d05da37dc352d4594e1a0d4d9cb2eb67798ae318de0d23d34926a447a37060c
[INFO] running `Command { std: "docker" "start" "-a" "4d05da37dc352d4594e1a0d4d9cb2eb67798ae318de0d23d34926a447a37060c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.5
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking slab v0.4.2
[INFO] [stderr]     Checking pin-utils v0.1.0-alpha.4
[INFO] [stderr]     Checking ak-rt v0.1.0
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]    Compiling proc-macro-hack v0.5.10
[INFO] [stderr]    Compiling ak-codegen v0.1.0
[INFO] [stderr]    Compiling async-trait v0.1.13
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking tokio v0.2.0-alpha.6
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.19
[INFO] [stderr]     Checking ak v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0635]: unknown feature `try_trait`
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(type_alias_impl_trait, arbitrary_self_types, try_trait)]
[INFO] [stdout]   |                                                         ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/context.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |         tx.send(fut.await);
[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] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `try_trait`
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(type_alias_impl_trait, arbitrary_self_types, try_trait)]
[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 `ak` due to 2 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/context.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 59 |         tx.send(fut.await);
[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] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "4d05da37dc352d4594e1a0d4d9cb2eb67798ae318de0d23d34926a447a37060c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d05da37dc352d4594e1a0d4d9cb2eb67798ae318de0d23d34926a447a37060c", kill_on_drop: false }`
[INFO] [stdout] 4d05da37dc352d4594e1a0d4d9cb2eb67798ae318de0d23d34926a447a37060c