[INFO] fetching crate errorcon 0.1.0...
[INFO] testing errorcon-0.1.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate errorcon 0.1.0 into /workspace/builds/worker-1-tc1/source
[INFO] started tweaking crates.io crate errorcon 0.1.0
[INFO] finished tweaking crates.io crate errorcon 0.1.0
[INFO] tweaked toml for crates.io crate errorcon 0.1.0 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate errorcon 0.1.0 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] 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 0e7c3852a971f4b39deedf72f0f4abd6f61c34328dcbc716c0a013c21b253575
[INFO] running `Command { std: "docker" "start" "-a" "0e7c3852a971f4b39deedf72f0f4abd6f61c34328dcbc716c0a013c21b253575", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0e7c3852a971f4b39deedf72f0f4abd6f61c34328dcbc716c0a013c21b253575", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0e7c3852a971f4b39deedf72f0f4abd6f61c34328dcbc716c0a013c21b253575", kill_on_drop: false }`
[INFO] [stdout] 0e7c3852a971f4b39deedf72f0f4abd6f61c34328dcbc716c0a013c21b253575
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] c84c46d9d4c3894c61c00592cc687dbee0a149953e81f00948077be5d9218ddc
[INFO] running `Command { std: "docker" "start" "-a" "c84c46d9d4c3894c61c00592cc687dbee0a149953e81f00948077be5d9218ddc", kill_on_drop: false }`
[INFO] [stderr]    Compiling errorcon v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:17:1
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(return_position_impl_trait_in_trait)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `return_position_impl_trait_in_trait` has been stable since `1.75.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `return_position_impl_trait_in_trait` has been stable since 1.75.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:17:12
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![feature(return_position_impl_trait_in_trait)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `errorcon` (lib) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "c84c46d9d4c3894c61c00592cc687dbee0a149953e81f00948077be5d9218ddc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c84c46d9d4c3894c61c00592cc687dbee0a149953e81f00948077be5d9218ddc", kill_on_drop: false }`
[INFO] [stdout] c84c46d9d4c3894c61c00592cc687dbee0a149953e81f00948077be5d9218ddc
