[INFO] cloning repository https://github.com/jlricon/rlinks
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jlricon/rlinks" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjlricon%2Frlinks", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjlricon%2Frlinks'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f39102c47e45b875a008756cdc87a590ff5f58c1
[INFO] testing jlricon/rlinks against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjlricon%2Frlinks" "/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/jlricon/rlinks 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/jlricon/rlinks
[INFO] finished tweaking git repo https://github.com/jlricon/rlinks
[INFO] tweaked toml for git repo https://github.com/jlricon/rlinks written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/jlricon/rlinks 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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/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] a3f455f1010e5a1ec7495ed041a410a7559a6cfaacb5b15c5656a59fd0783b79
[INFO] running `Command { std: "docker" "start" "-a" "a3f455f1010e5a1ec7495ed041a410a7559a6cfaacb5b15c5656a59fd0783b79", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a3f455f1010e5a1ec7495ed041a410a7559a6cfaacb5b15c5656a59fd0783b79", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a3f455f1010e5a1ec7495ed041a410a7559a6cfaacb5b15c5656a59fd0783b79", kill_on_drop: false }`
[INFO] [stdout] a3f455f1010e5a1ec7495ed041a410a7559a6cfaacb5b15c5656a59fd0783b79
[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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8d036abe4b9d4786c3be46b774924d0c4e37779d16893869f37e5f8cf0bef467
[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" "8d036abe4b9d4786c3be46b774924d0c4e37779d16893869f37e5f8cf0bef467", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling autocfg v0.1.6
[INFO] [stderr]    Compiling proc-macro2 v1.0.2
[INFO] [stderr]    Compiling cc v1.0.42
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling pkg-config v0.3.15
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling getrandom v0.1.11
[INFO] [stderr]    Compiling serde v1.0.99
[INFO] [stderr]    Compiling string_cache_shared v0.3.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]    Compiling ryu v1.0.0
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling new_debug_unreachable v1.0.3
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling unicode-width v0.1.6
[INFO] [stderr]    Compiling pin-utils v0.1.0-alpha.4
[INFO] [stderr]    Compiling curl v0.4.23
[INFO] [stderr]    Compiling scopeguard v1.0.0
[INFO] [stderr]    Compiling bit-vec v0.5.1
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling quick-error v1.2.2
[INFO] [stderr]    Compiling isahc v0.7.3
[INFO] [stderr]    Compiling termcolor v1.0.5
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling futf v0.1.4
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling lock_api v0.3.1
[INFO] [stderr]    Compiling unicode-normalization v0.1.8
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[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 humantime v1.3.0
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling bit-set v0.5.1
[INFO] [stderr]    Compiling tendril v0.4.1
[INFO] [stderr]    Compiling phf v0.7.24
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling aho-corasick v0.7.6
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling sluice v0.4.2
[INFO] [stderr]    Compiling libz-sys v1.0.25
[INFO] [stderr]    Compiling libnghttp2-sys v0.1.2
[INFO] [stderr]    Compiling openssl-sys v0.9.49
[INFO] [stderr]    Compiling curl-sys v0.4.21
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling atty v0.2.13
[INFO] [stderr]    Compiling termios v0.3.1
[INFO] [stderr]    Compiling time v0.1.42
[INFO] [stderr]    Compiling clicolors-control v1.0.1
[INFO] [stderr]    Compiling socket2 v0.3.11
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling clap v2.33.1
[INFO] [stderr]    Compiling url v2.1.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling http v0.1.18
[INFO] [stderr]    Compiling rand v0.7.0
[INFO] [stderr]    Compiling number_prefix v0.2.8
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling string_cache_codegen v0.4.2
[INFO] [stderr]    Compiling phf_codegen v0.7.24
[INFO] [stderr]    Compiling console v0.8.0
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling chrono v0.4.9
[INFO] [stderr]    Compiling indicatif v0.11.0
[INFO] [stderr]    Compiling string_cache v0.7.3
[INFO] [stderr]    Compiling serde_json v1.0.40
[INFO] [stderr]    Compiling proc-macro-hack v0.5.9
[INFO] [stderr]    Compiling serde_derive v1.0.99
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling html5ever v0.23.0
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.18
[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-util-preview-0.3.0-alpha.18/src/lib.rs:4:38
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![cfg_attr(feature = "async-await", feature(async_await))]
[INFO] [stdout]   |                                      ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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-util-preview`
[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" "8d036abe4b9d4786c3be46b774924d0c4e37779d16893869f37e5f8cf0bef467", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8d036abe4b9d4786c3be46b774924d0c4e37779d16893869f37e5f8cf0bef467", kill_on_drop: false }`
[INFO] [stdout] 8d036abe4b9d4786c3be46b774924d0c4e37779d16893869f37e5f8cf0bef467