[INFO] fetching crate observatory 0.1.7...
[INFO] testing observatory-0.1.7 against 1.59.0 for beta-1.60-1
[INFO] extracting crate observatory 0.1.7 into /workspace/builds/worker-26/source
[INFO] validating manifest of crates.io crate observatory 0.1.7 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[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-26/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-26/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-26/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 76541583ab6c13a5bcdcd97a25cf911552ab8dc9070ca6fe6c916bf576e3ad5a
[INFO] running `Command { std: "docker" "start" "-a" "76541583ab6c13a5bcdcd97a25cf911552ab8dc9070ca6fe6c916bf576e3ad5a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "76541583ab6c13a5bcdcd97a25cf911552ab8dc9070ca6fe6c916bf576e3ad5a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "76541583ab6c13a5bcdcd97a25cf911552ab8dc9070ca6fe6c916bf576e3ad5a", kill_on_drop: false }`
[INFO] [stdout] 76541583ab6c13a5bcdcd97a25cf911552ab8dc9070ca6fe6c916bf576e3ad5a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-26/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-26/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" "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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 26051de599740a18e966ea8301ef13ed14d9fa2c7e9c1d041f12855dfcd6ae14
[INFO] running `Command { std: "docker" "start" "-a" "26051de599740a18e966ea8301ef13ed14d9fa2c7e9c1d041f12855dfcd6ae14", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-queue v0.3.4
[INFO] [stderr]    Compiling crossbeam-channel v0.5.2
[INFO] [stderr]    Compiling crossbeam-deque v0.8.1
[INFO] [stderr]    Compiling crossbeam v0.8.1
[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] error: aborting due to 5 previous errors
[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` due to 6 previous errors
[INFO] running `Command { std: "docker" "inspect" "26051de599740a18e966ea8301ef13ed14d9fa2c7e9c1d041f12855dfcd6ae14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "26051de599740a18e966ea8301ef13ed14d9fa2c7e9c1d041f12855dfcd6ae14", kill_on_drop: false }`
[INFO] [stdout] 26051de599740a18e966ea8301ef13ed14d9fa2c7e9c1d041f12855dfcd6ae14