[INFO] cloning repository https://github.com/emk/drop-async-examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/emk/drop-async-examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femk%2Fdrop-async-examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femk%2Fdrop-async-examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 48d2b3609ae85fbba497b5134135ded3fbedbb32
[INFO] testing emk/drop-async-examples against beta-2021-01-01 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Femk%2Fdrop-async-examples" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/emk/drop-async-examples on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/emk/drop-async-examples
[INFO] finished tweaking git repo https://github.com/emk/drop-async-examples
[INFO] tweaked toml for git repo https://github.com/emk/drop-async-examples written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/emk/drop-async-examples already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-sync v0.1.3
[INFO] [stderr]   Downloaded tokio-async-await v0.1.5
[INFO] [stderr]   Downloaded syn v0.15.28
[INFO] running `Command { std: "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" "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" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 130e0d690b25fa3719aacfa371579e1ea84e01c765688d5e98785f01f99dcfc1
[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" "130e0d690b25fa3719aacfa371579e1ea84e01c765688d5e98785f01f99dcfc1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "130e0d690b25fa3719aacfa371579e1ea84e01c765688d5e98785f01f99dcfc1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "130e0d690b25fa3719aacfa371579e1ea84e01c765688d5e98785f01f99dcfc1", kill_on_drop: false }`
[INFO] [stdout] 130e0d690b25fa3719aacfa371579e1ea84e01c765688d5e98785f01f99dcfc1
[INFO] running `Command { std: "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" "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" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6cb0e069789e6610b35c95aaa7f2330fb98286ae3938dd76d0ffdf92999d3de3
[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" "6cb0e069789e6610b35c95aaa7f2330fb98286ae3938dd76d0ffdf92999d3de3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.50
[INFO] [stderr]    Compiling cfg-if v0.1.7
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling rand_core v0.4.0
[INFO] [stderr]    Compiling futures v0.1.25
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling byteorder v1.3.1
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling proc-macro2 v0.4.27
[INFO] [stderr]    Compiling smallvec v0.6.9
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling memoffset v0.2.1
[INFO] [stderr]    Compiling cc v1.0.30
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling rustc-demangle v0.1.13
[INFO] [stderr]    Compiling owning_ref v0.4.0
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/futures-0.1.25/src/lib.rs:161:34
[INFO] [stdout]     |
[INFO] [stdout] 161 | #![cfg_attr(feature = "nightly", feature(pin))]
[INFO] [stdout]     |                                  ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.3
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling lock_api v0.1.5
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling backtrace v0.3.14
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling rustc_version v0.2.3
[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 `futures`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "6cb0e069789e6610b35c95aaa7f2330fb98286ae3938dd76d0ffdf92999d3de3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6cb0e069789e6610b35c95aaa7f2330fb98286ae3938dd76d0ffdf92999d3de3", kill_on_drop: false }`
[INFO] [stdout] 6cb0e069789e6610b35c95aaa7f2330fb98286ae3938dd76d0ffdf92999d3de3