[INFO] cloning repository https://github.com/nikomatsakis/mathema
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nikomatsakis/mathema" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fmathema", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fmathema'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 57c64e74bf8c582641dc83b0a1a3932e32e045d0
[INFO] testing nikomatsakis/mathema against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnikomatsakis%2Fmathema" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/nikomatsakis/mathema on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-7/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/nikomatsakis/mathema
[INFO] finished tweaking git repo https://github.com/nikomatsakis/mathema
[INFO] tweaked toml for git repo https://github.com/nikomatsakis/mathema written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/nikomatsakis/mathema already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3f52d67ce3b1f6d21dff1f5523aed749098c85abd1ae1728bc5c4bacd30b3200
[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" "3f52d67ce3b1f6d21dff1f5523aed749098c85abd1ae1728bc5c4bacd30b3200", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3f52d67ce3b1f6d21dff1f5523aed749098c85abd1ae1728bc5c4bacd30b3200", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f52d67ce3b1f6d21dff1f5523aed749098c85abd1ae1728bc5c4bacd30b3200", kill_on_drop: false }`
[INFO] [stdout] 3f52d67ce3b1f6d21dff1f5523aed749098c85abd1ae1728bc5c4bacd30b3200
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] eeed05d4467636eb6b2019c4e46f2869fe32f074edf8ebd5515dce10c69a804c
[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" "eeed05d4467636eb6b2019c4e46f2869fe32f074edf8ebd5515dce10c69a804c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.54
[INFO] [stderr]    Compiling cfg-if v0.1.7
[INFO] [stderr]    Compiling serde v1.0.91
[INFO] [stderr]    Compiling cc v1.0.36
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling slog v2.4.1
[INFO] [stderr]    Compiling string v0.1.3
[INFO] [stderr]    Compiling remove_dir_all v0.5.1
[INFO] [stderr]    Compiling rustc-demangle v0.1.14
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling tokio-trace-core v0.1.0
[INFO] [stderr]    Compiling backtrace v0.3.15
[INFO] [stderr]    Compiling tokio-sync v0.1.5
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling buf_redux v0.8.1
[INFO] [stderr]    Compiling twoway v0.1.8
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling rust-embed-impl v4.4.0
[INFO] [stderr]    Compiling structopt-derive v0.1.6
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling crossbeam-utils v0.6.5
[INFO] [stderr]    Compiling regex v1.1.7
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling synstructure v0.10.1
[INFO] [stderr]    Compiling log v0.3.9
[INFO] [stderr]    Compiling want v0.0.6
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling tokio-executor v0.1.7
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.1
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling mime v0.2.6
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling tokio-timer v0.2.10
[INFO] [stderr]    Compiling tokio-current-thread v0.1.6
[INFO] [stderr]    Compiling slog-async v2.3.0
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling libz-sys v1.0.25
[INFO] [stderr]    Compiling openssl-sys v0.9.46
[INFO] [stderr]    Compiling libssh2-sys v0.2.11
[INFO] [stderr]    Compiling curl-sys v0.4.18
[INFO] [stderr]    Compiling backtrace-sys v0.1.28
[INFO] [stderr]    Compiling libgit2-sys v0.7.11
[INFO] [stderr]    Compiling rust-embed v4.4.0
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling iovec v0.1.2
[INFO] [stderr]    Compiling num_cpus v1.10.0
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling time v0.1.42
[INFO] [stderr]    Compiling rand v0.4.6
[INFO] [stderr]    Compiling dirs v1.0.5
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling isatty v0.1.9
[INFO] [stderr]    Compiling nix v0.9.0
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling env_logger v0.6.1
[INFO] [stderr]    Compiling futures-cpupool v0.1.8
[INFO] [stderr]    Compiling term v0.5.2
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling mio v0.6.16
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]    Compiling cookie v0.11.1
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling tokio-io v0.1.12
[INFO] [stderr]    Compiling http v0.1.17
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling tokio-threadpool v0.1.14
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling chrono v0.4.6
[INFO] [stderr]    Compiling serde_urlencoded v0.5.5
[INFO] [stderr]    Compiling serde_json v1.0.39
[INFO] [stderr]    Compiling string-interner v0.6.3
[INFO] [stderr]    Compiling uuid v0.6.5
[INFO] [stderr]    Compiling ron v0.2.2
[INFO] [stderr]    Compiling phf_codegen v0.7.24
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.16
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling failure v0.1.5
[INFO] [stderr]    Compiling atomicwrites v0.1.5
[INFO] [stderr]    Compiling mime_guess v1.8.7
[INFO] [stderr]    Compiling slog-term v2.4.0
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]    Compiling structopt v0.1.7
[INFO] [stderr]    Compiling h2 v0.1.18
[INFO] [stderr]    Compiling http-service v0.2.0
[INFO] [stdout] error: incorrect use of `await`
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/http-service-0.2.0/src/lib.rs:102:33
[INFO] [stdout]     |
[INFO] [stdout] 102 |         while let Some(chunk) = await!(self.next()) {
[INFO] [stdout]     |                                 ^^^^^^^^^^^^^^^^^^^ help: `await` is a postfix operation: `self.next().await`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/http-service-0.2.0/src/lib.rs:60:25
[INFO] [stdout]    |
[INFO] [stdout] 60 | #![feature(async_await, await_macro, arbitrary_self_types)]
[INFO] [stdout]    |                         ^^^^^^^^^^^ feature has been removed
[INFO] [stdout]    |
[INFO] [stdout]    = note: subsumed by `.await` syntax
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling parking_lot v0.7.1
[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/http-service-0.2.0/src/lib.rs:60:1
[INFO] [stdout]    |
[INFO] [stdout] 60 | #![feature(async_await, await_macro, arbitrary_self_types)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `http-service` due to 4 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "eeed05d4467636eb6b2019c4e46f2869fe32f074edf8ebd5515dce10c69a804c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "eeed05d4467636eb6b2019c4e46f2869fe32f074edf8ebd5515dce10c69a804c", kill_on_drop: false }`
[INFO] [stdout] eeed05d4467636eb6b2019c4e46f2869fe32f074edf8ebd5515dce10c69a804c