[INFO] fetching crate observatory 0.1.7...
[INFO] testing observatory-0.1.7 against 1.91.0 for beta-1.92-2
[INFO] extracting crate observatory 0.1.7 into /workspace/builds/worker-1-tc1/source
[INFO] started tweaking crates.io crate observatory 0.1.7
[INFO] finished tweaking crates.io crate observatory 0.1.7
[INFO] tweaked toml for crates.io crate observatory 0.1.7 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate observatory 0.1.7 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "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" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 6 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c4c6ddc9bb8cd2606a3776881466cf12bab9eae693327770a8d8255b1a5e608
[INFO] running `Command { std: "docker" "start" "-a" "1c4c6ddc9bb8cd2606a3776881466cf12bab9eae693327770a8d8255b1a5e608", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c4c6ddc9bb8cd2606a3776881466cf12bab9eae693327770a8d8255b1a5e608", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c4c6ddc9bb8cd2606a3776881466cf12bab9eae693327770a8d8255b1a5e608", kill_on_drop: false }`
[INFO] [stdout] 1c4c6ddc9bb8cd2606a3776881466cf12bab9eae693327770a8d8255b1a5e608
[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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3097408a9f3c299ea92cf99a6ec28d646f2e6b300d35cab84a1d09b941d25564
[INFO] running `Command { std: "docker" "start" "-a" "3097408a9f3c299ea92cf99a6ec28d646f2e6b300d35cab84a1d09b941d25564", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-deque v0.8.6
[INFO] [stderr]    Compiling crossbeam-channel v0.5.15
[INFO] [stderr]    Compiling crossbeam-queue v0.3.12
[INFO] [stderr]    Compiling crossbeam v0.8.4
[INFO] [stderr]    Compiling observatory v0.1.7 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(arc_new_cyclic)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(unsize)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(coerce_unsized)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(min_specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `arc_new_cyclic` has been stable since 1.60.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(arc_new_cyclic)]
[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 `observatory` (lib) due to 5 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "3097408a9f3c299ea92cf99a6ec28d646f2e6b300d35cab84a1d09b941d25564", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3097408a9f3c299ea92cf99a6ec28d646f2e6b300d35cab84a1d09b941d25564", kill_on_drop: false }`
[INFO] [stdout] 3097408a9f3c299ea92cf99a6ec28d646f2e6b300d35cab84a1d09b941d25564