[INFO] cloning repository https://github.com/Emerentius/drain_experiments
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Emerentius/drain_experiments" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEmerentius%2Fdrain_experiments"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEmerentius%2Fdrain_experiments'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 5d693978cc0ae5cbb701145ae3d12f15e8ac80e7
[INFO] testing Emerentius/drain_experiments against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEmerentius%2Fdrain_experiments" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Emerentius/drain_experiments on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/Emerentius/drain_experiments
[INFO] finished tweaking git repo https://github.com/Emerentius/drain_experiments
[INFO] tweaked toml for git repo https://github.com/Emerentius/drain_experiments written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/Emerentius/drain_experiments already has a lockfile, it will not be regenerated
[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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] cd6860f77b961869ade68cfa64bc471957a380ea8176bbea7eb85bdb67b6379a
[INFO] running `"docker" "start" "-a" "cd6860f77b961869ade68cfa64bc471957a380ea8176bbea7eb85bdb67b6379a"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling try_drain v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(drain_filter)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused imports: `Exhausting`, `IteratorExt`
[INFO] [stderr]   --> src/lib.rs:11:18
[INFO] [stderr]    |
[INFO] [stderr] 11 | use exhausting::{Exhausting, IteratorExt};
[INFO] [stderr]    |                  ^^^^^^^^^^  ^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `StreamElement`
[INFO] [stderr]   --> src/lib.rs:14:44
[INFO] [stderr]    |
[INFO] [stderr] 14 | use drain_element_streaming::{StreamDrain, StreamElement};
[INFO] [stderr]    |                                            ^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `CursorIter`
[INFO] [stderr]   --> src/lib.rs:17:22
[INFO] [stderr]    |
[INFO] [stderr] 17 | use cursor::{Cursor, CursorIter};
[INFO] [stderr]    |                      ^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error; 3 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `try_drain`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "cd6860f77b961869ade68cfa64bc471957a380ea8176bbea7eb85bdb67b6379a"`
[INFO] running `"docker" "rm" "-f" "cd6860f77b961869ade68cfa64bc471957a380ea8176bbea7eb85bdb67b6379a"`
[INFO] [stdout] cd6860f77b961869ade68cfa64bc471957a380ea8176bbea7eb85bdb67b6379a