[INFO] cloning repository https://github.com/tahmidsadik112/rust-async-await-examples
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tahmidsadik112/rust-async-await-examples" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftahmidsadik112%2Frust-async-await-examples", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftahmidsadik112%2Frust-async-await-examples'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 858988e00d47ddf9448194ebd63ba1dee4451625
[INFO] testing tahmidsadik112/rust-async-await-examples against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftahmidsadik112%2Frust-async-await-examples" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tahmidsadik112/rust-async-await-examples 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 git repo https://github.com/tahmidsadik112/rust-async-await-examples
[INFO] finished tweaking git repo https://github.com/tahmidsadik112/rust-async-await-examples
[INFO] tweaked toml for git repo https://github.com/tahmidsadik112/rust-async-await-examples written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/tahmidsadik112/rust-async-await-examples already has a lockfile, it will not be regenerated
[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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/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] 43f67711a85e205d8319b0f1a71339ae26f45a01736f0d6313d4487d4cf8bb9b
[INFO] running `Command { std: "docker" "start" "-a" "43f67711a85e205d8319b0f1a71339ae26f45a01736f0d6313d4487d4cf8bb9b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "43f67711a85e205d8319b0f1a71339ae26f45a01736f0d6313d4487d4cf8bb9b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43f67711a85e205d8319b0f1a71339ae26f45a01736f0d6313d4487d4cf8bb9b", kill_on_drop: false }`
[INFO] [stdout] 43f67711a85e205d8319b0f1a71339ae26f45a01736f0d6313d4487d4cf8bb9b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", 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] c879c3c2b5c3c6c611f4a5b1133eb466ba08815a9f5ab6add4ba11c7877466fc
[INFO] running `Command { std: "docker" "start" "-a" "c879c3c2b5c3c6c611f4a5b1133eb466ba08815a9f5ab6add4ba11c7877466fc", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.50
[INFO] [stderr]    Compiling cfg-if v0.1.7
[INFO] [stderr]    Compiling rand_core v0.4.0
[INFO] [stderr]    Compiling autocfg v0.1.2
[INFO] [stderr]    Compiling futures v0.1.25
[INFO] [stderr]    Compiling lazy_static v1.3.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling byteorder v1.3.1
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling smallvec v0.6.9
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling proc-macro2 v0.4.27
[INFO] [stderr]    Compiling arrayvec v0.4.10
[INFO] [stderr]    Compiling pkg-config v0.3.14
[INFO] [stderr]    Compiling nodrop v0.1.13
[INFO] [stderr]    Compiling cc v1.0.31
[INFO] [stderr]    Compiling either v1.5.1
[INFO] [stderr]    Compiling syn v0.15.29
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable 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 itoa v0.4.3
[INFO] [stderr]    Compiling httparse v1.3.3
[INFO] [stderr]    Compiling openssl v0.10.20
[INFO] [stderr]    Compiling indexmap v1.0.2
[INFO] [stderr]    Compiling try-lock v0.2.2
[INFO] [stderr]    Compiling bitflags v1.0.4
[INFO] [stderr]    Compiling string v0.1.3
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling native-tls v0.2.2
[INFO] [stderr]    Compiling openssl-probe v0.1.2
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling owning_ref v0.4.0
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling tokio-trace-core v0.1.0
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.3
[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" "c879c3c2b5c3c6c611f4a5b1133eb466ba08815a9f5ab6add4ba11c7877466fc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c879c3c2b5c3c6c611f4a5b1133eb466ba08815a9f5ab6add4ba11c7877466fc", kill_on_drop: false }`
[INFO] [stdout] c879c3c2b5c3c6c611f4a5b1133eb466ba08815a9f5ab6add4ba11c7877466fc