[INFO] fetching crate debug_sat 0.4.0...
[INFO] testing debug_sat-0.4.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate debug_sat 0.4.0 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate debug_sat 0.4.0 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate debug_sat 0.4.0
[INFO] finished tweaking crates.io crate debug_sat 0.4.0
[INFO] tweaked toml for crates.io crate debug_sat 0.4.0 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 08ed87518a128084a2e2ce1590a3d0de35506197b19fbedce3eecfbf8bca96e1
[INFO] running `Command { std: "docker" "start" "-a" "08ed87518a128084a2e2ce1590a3d0de35506197b19fbedce3eecfbf8bca96e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "08ed87518a128084a2e2ce1590a3d0de35506197b19fbedce3eecfbf8bca96e1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08ed87518a128084a2e2ce1590a3d0de35506197b19fbedce3eecfbf8bca96e1", kill_on_drop: false }`
[INFO] [stdout] 08ed87518a128084a2e2ce1590a3d0de35506197b19fbedce3eecfbf8bca96e1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c459a763102a63bbb1b3d83e8ab0148e40a446e06d40c867865a0095a2a8d568
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "c459a763102a63bbb1b3d83e8ab0148e40a446e06d40c867865a0095a2a8d568", kill_on_drop: false }`
[INFO] [stderr]    Compiling debug_sat v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.72s
[INFO] running `Command { std: "docker" "inspect" "c459a763102a63bbb1b3d83e8ab0148e40a446e06d40c867865a0095a2a8d568", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c459a763102a63bbb1b3d83e8ab0148e40a446e06d40c867865a0095a2a8d568", kill_on_drop: false }`
[INFO] [stdout] c459a763102a63bbb1b3d83e8ab0148e40a446e06d40c867865a0095a2a8d568
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 69b99c6308cb91b95451d1ed2162f9f076f4c30c81a77d14cf31b5cdf0c2a2ed
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "69b99c6308cb91b95451d1ed2162f9f076f4c30c81a77d14cf31b5cdf0c2a2ed", kill_on_drop: false }`
[INFO] [stderr]    Compiling debug_sat v0.4.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:115:19
[INFO] [stdout]     |
[INFO] [stdout] 115 | #![cfg_attr(test, feature(test))]
[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 `debug_sat`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "69b99c6308cb91b95451d1ed2162f9f076f4c30c81a77d14cf31b5cdf0c2a2ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "69b99c6308cb91b95451d1ed2162f9f076f4c30c81a77d14cf31b5cdf0c2a2ed", kill_on_drop: false }`
[INFO] [stdout] 69b99c6308cb91b95451d1ed2162f9f076f4c30c81a77d14cf31b5cdf0c2a2ed