[INFO] fetching crate modus_ponens 0.11.2...
[INFO] testing modus_ponens-0.11.2 against 1.44.0 for beta-1.45-1
[INFO] extracting crate modus_ponens 0.11.2 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate modus_ponens 0.11.2 on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate modus_ponens 0.11.2
[INFO] finished tweaking crates.io crate modus_ponens 0.11.2
[INFO] tweaked toml for crates.io crate modus_ponens 0.11.2 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 538328c3fe46452ae447092b57e0d2ea39eadfa66c8978a34c5c2b836a55cc44
[INFO] running `"docker" "start" "-a" "538328c3fe46452ae447092b57e0d2ea39eadfa66c8978a34c5c2b836a55cc44"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling syn v1.0.30
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling pest_meta v2.1.3
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling pest_generator v2.1.3
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]    Compiling modus_ponens v0.11.2 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:20:1
[INFO] [stderr]    |
[INFO] [stderr] 20 | #![feature(hash_set_entry)]
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `modus_ponens`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "538328c3fe46452ae447092b57e0d2ea39eadfa66c8978a34c5c2b836a55cc44"`
[INFO] running `"docker" "rm" "-f" "538328c3fe46452ae447092b57e0d2ea39eadfa66c8978a34c5c2b836a55cc44"`
[INFO] [stdout] 538328c3fe46452ae447092b57e0d2ea39eadfa66c8978a34c5c2b836a55cc44