[INFO] fetching crate loader-rs 0.7.0...
[INFO] testing loader-rs-0.7.0 against master#a77da2d454e6caa227a85b16410b95f93495e7e0 for pr-91031
[INFO] extracting crate loader-rs 0.7.0 into /workspace/builds/worker-64/source
[INFO] validating manifest of crates.io crate loader-rs 0.7.0 on toolchain a77da2d454e6caa227a85b16410b95f93495e7e0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-64/source/rust-toolchain
[INFO] started tweaking crates.io crate loader-rs 0.7.0
[INFO] finished tweaking crates.io crate loader-rs 0.7.0
[INFO] tweaked toml for crates.io crate loader-rs 0.7.0 written to /workspace/builds/worker-64/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "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" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "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-64/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/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" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b59d172583df4d1f7f54dd4ae76b1be43d9ee2556950b894abcd4a0173fb16b1
[INFO] running `Command { std: "docker" "start" "-a" "b59d172583df4d1f7f54dd4ae76b1be43d9ee2556950b894abcd4a0173fb16b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b59d172583df4d1f7f54dd4ae76b1be43d9ee2556950b894abcd4a0173fb16b1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b59d172583df4d1f7f54dd4ae76b1be43d9ee2556950b894abcd4a0173fb16b1", kill_on_drop: false }`
[INFO] [stdout] b59d172583df4d1f7f54dd4ae76b1be43d9ee2556950b894abcd4a0173fb16b1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-64/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" "+a77da2d454e6caa227a85b16410b95f93495e7e0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 314fac146c980d9047976d431a35d0f7062f387fd192475c5893d927e852b980
[INFO] running `Command { std: "docker" "start" "-a" "314fac146c980d9047976d431a35d0f7062f387fd192475c5893d927e852b980", 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] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling libc v0.2.108
[INFO] [stderr]    Compiling syn v1.0.81
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[INFO] [stderr]    Compiling futures-sink v0.3.17
[INFO] [stderr]    Compiling futures-channel v0.3.17
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[INFO] [stderr]    Compiling socket2 v0.3.19
[INFO] [stderr]    Compiling unicode-normalization v0.1.19
[INFO] [stderr]    Compiling parking_lot v0.11.2
[INFO] [stderr]    Compiling flate2 v1.0.22
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[INFO] [stderr]    Compiling async-compression v0.3.8
[INFO] [stderr]    Compiling tokio v0.2.25
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[INFO] [stderr]    Compiling http-body v0.3.1
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[INFO] [stderr]    Compiling darling_core v0.13.0
[INFO] [stderr]    Compiling tokio-util v0.3.1
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[INFO] [stderr]    Compiling darling_macro v0.13.0
[INFO] [stderr]    Compiling pin-project v1.0.8
[INFO] [stderr]    Compiling tracing-futures v0.2.5
[INFO] [stderr]    Compiling darling v0.13.0
[INFO] [stderr]    Compiling cached_proc_macro v0.7.1
[INFO] [stderr]    Compiling h2 v0.2.7
[INFO] [stderr]    Compiling futures-executor v0.3.17
[INFO] [stderr]    Compiling futures v0.3.17
[INFO] [stderr]    Compiling cached v0.26.2
[INFO] [stderr]    Compiling hyper v0.13.10
[INFO] [stderr]    Compiling hyper-tls v0.4.3
[INFO] [stderr]    Compiling reqwest v0.10.10
[INFO] [stderr]    Compiling loader-rs v0.7.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:43:12
[INFO] [stdout]    |
[INFO] [stdout] 43 | #![feature(specialization)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:36:5
[INFO] [stdout]    |
[INFO] [stdout] 36 |     warnings,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(incomplete_features)]` implied by `#[deny(warnings)]`
[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] error: unused result
[INFO] [stdout]   --> src/thread_safe_cache.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         self.0.lock().cache_set(key.clone(), value);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:33:5
[INFO] [stdout]    |
[INFO] [stdout] 33 |     unused_results,
[INFO] [stdout]    |     ^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `loader-rs` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "314fac146c980d9047976d431a35d0f7062f387fd192475c5893d927e852b980", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "314fac146c980d9047976d431a35d0f7062f387fd192475c5893d927e852b980", kill_on_drop: false }`
[INFO] [stdout] 314fac146c980d9047976d431a35d0f7062f387fd192475c5893d927e852b980