[INFO] crate gen-iter 0.2.0 is already in cache
[INFO] testing gen-iter-0.2.0 against 1.44.0 for beta-1.45-1
[INFO] extracting crate gen-iter 0.2.0 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate gen-iter 0.2.0 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 gen-iter 0.2.0
[INFO] finished tweaking crates.io crate gen-iter 0.2.0
[INFO] tweaked toml for crates.io crate gen-iter 0.2.0 written to /workspace/builds/worker-14/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-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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] [stdout] 1e53053bc33829022ea07fc0778341bd56df694ecc260246f2e75c4368e47c73
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "1e53053bc33829022ea07fc0778341bd56df694ecc260246f2e75c4368e47c73"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling gen-iter v0.2.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:33:1
[INFO] [stderr]    |
[INFO] [stderr] 33 | #![feature(generators, generator_trait)]
[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 `gen-iter`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "1e53053bc33829022ea07fc0778341bd56df694ecc260246f2e75c4368e47c73"`
[INFO] running `"docker" "rm" "-f" "1e53053bc33829022ea07fc0778341bd56df694ecc260246f2e75c4368e47c73"`
[INFO] [stdout] 1e53053bc33829022ea07fc0778341bd56df694ecc260246f2e75c4368e47c73