[INFO] fetching crate levitas_client 2.0.0...
[INFO] testing levitas_client-2.0.0 against 1.75.0 for beta-1.76-1
[INFO] extracting crate levitas_client 2.0.0 into /workspace/builds/worker-5-tc1/source
[INFO] validating manifest of crates.io crate levitas_client 2.0.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate levitas_client 2.0.0
[INFO] finished tweaking crates.io crate levitas_client 2.0.0
[INFO] tweaked toml for crates.io crate levitas_client 2.0.0 written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 624dca2e8cd99510ba9f024f8a8d7d2c216e6a330f4172f4f96b32549c493d28
[INFO] running `Command { std: "docker" "start" "-a" "624dca2e8cd99510ba9f024f8a8d7d2c216e6a330f4172f4f96b32549c493d28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "624dca2e8cd99510ba9f024f8a8d7d2c216e6a330f4172f4f96b32549c493d28", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "624dca2e8cd99510ba9f024f8a8d7d2c216e6a330f4172f4f96b32549c493d28", kill_on_drop: false }`
[INFO] [stdout] 624dca2e8cd99510ba9f024f8a8d7d2c216e6a330f4172f4f96b32549c493d28
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bab28b86b3f682f36307b41be82ca538c6e55ceed76851728df85e7ae3b55358
[INFO] running `Command { std: "docker" "start" "-a" "bab28b86b3f682f36307b41be82ca538c6e55ceed76851728df85e7ae3b55358", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.75
[INFO] [stderr]    Compiling unicode-ident v1.0.12
[INFO] [stderr]    Compiling serde v1.0.194
[INFO] [stderr]    Compiling serde_json v1.0.111
[INFO] [stderr]    Compiling ryu v1.0.16
[INFO] [stderr]    Compiling itoa v1.0.10
[INFO] [stderr]    Compiling quote v1.0.35
[INFO] [stderr]    Compiling syn v2.0.48
[INFO] [stderr]    Compiling serde_derive v1.0.194
[INFO] [stderr]    Compiling levitas_client v2.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(option_get_or_insert_default)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `levitas_client` (lib) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "bab28b86b3f682f36307b41be82ca538c6e55ceed76851728df85e7ae3b55358", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bab28b86b3f682f36307b41be82ca538c6e55ceed76851728df85e7ae3b55358", kill_on_drop: false }`
[INFO] [stdout] bab28b86b3f682f36307b41be82ca538c6e55ceed76851728df85e7ae3b55358
