[INFO] fetching crate tarpc-lib 0.7.0...
[INFO] testing tarpc-lib-0.7.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate tarpc-lib 0.7.0 into /workspace/builds/worker-6-tc1/source
[INFO] started tweaking crates.io crate tarpc-lib 0.7.0
[INFO] finished tweaking crates.io crate tarpc-lib 0.7.0
[INFO] tweaked toml for crates.io crate tarpc-lib 0.7.0 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate tarpc-lib 0.7.0 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 60 packages to latest compatible versions
[INFO] [stderr]       Adding env_logger v0.6.2 (available: v0.11.8)
[INFO] [stderr]       Adding humantime v1.3.0 (available: v2.3.0)
[INFO] [stderr]       Adding rand v0.7.3 (available: v0.9.2)
[INFO] [stderr]       Adding tokio v0.2.25 (available: v1.47.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-timer v0.3.0-alpha.6
[INFO] [stderr]   Downloaded tarpc-trace v0.3.0
[INFO] [stderr]   Downloaded futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded tokio-sync v0.2.0-alpha.6
[INFO] [stderr]   Downloaded futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded tokio-executor v0.2.0-alpha.6
[INFO] [stderr]   Downloaded futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded futures-test-preview v0.3.0-alpha.19
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 24f08619448947166a43d7fbe7a09821efd78cf49c4467b79f51cef57d851450
[INFO] running `Command { std: "docker" "start" "-a" "24f08619448947166a43d7fbe7a09821efd78cf49c4467b79f51cef57d851450", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "24f08619448947166a43d7fbe7a09821efd78cf49c4467b79f51cef57d851450", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "24f08619448947166a43d7fbe7a09821efd78cf49c4467b79f51cef57d851450", kill_on_drop: false }`
[INFO] [stdout] 24f08619448947166a43d7fbe7a09821efd78cf49c4467b79f51cef57d851450
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dad95bdb8759fb86c92a6d526df08d1ee1128221d0c075dda62c6808afe27c7b
[INFO] running `Command { std: "docker" "start" "-a" "dad95bdb8759fb86c92a6d526df08d1ee1128221d0c075dda62c6808afe27c7b", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling tarpc-trace v0.3.0
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling tokio-sync v0.2.0-alpha.6
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling tokio-executor v0.2.0-alpha.6
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling tokio-timer v0.3.0-alpha.6
[INFO] [stderr]    Compiling tarpc-lib v0.7.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(weak_counts, non_exhaustive, trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `non_exhaustive` has been stable since `1.40.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `non_exhaustive` has been stable since 1.40.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:7:25
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(weak_counts, non_exhaustive, trait_alias)]
[INFO] [stdout]   |                         ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `weak_counts` has been stable since 1.41.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:7:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(weak_counts, non_exhaustive, trait_alias)]
[INFO] [stdout]   |            ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tarpc-lib` (lib) due to 1 previous error; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "dad95bdb8759fb86c92a6d526df08d1ee1128221d0c075dda62c6808afe27c7b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dad95bdb8759fb86c92a6d526df08d1ee1128221d0c075dda62c6808afe27c7b", kill_on_drop: false }`
[INFO] [stdout] dad95bdb8759fb86c92a6d526df08d1ee1128221d0c075dda62c6808afe27c7b