[INFO] fetching crate async-coap 0.1.0...
[INFO] checking async-coap-0.1.0 against 1.95.0 for pr-155915
[INFO] extracting crate async-coap 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate async-coap 0.1.0
[INFO] finished tweaking crates.io crate async-coap 0.1.0
[INFO] tweaked toml for crates.io crate async-coap 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate async-coap 0.1.0 on toolchain 1.95.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 70 packages to latest compatible versions
[INFO] [stderr]       Adding futures-channel-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-core-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-executor-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-io-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-join-macro-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-select-macro-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-sink-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding futures-timer v0.3.0 (available: v3.0.3)
[INFO] [stderr]       Adding futures-util-preview v0.3.0-alpha.18 (available: v0.3.0-alpha.19)
[INFO] [stderr]       Adding num v0.2.1 (available: v0.4.3)
[INFO] [stderr]       Adding rand v0.6.5 (available: v0.10.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded futures-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-timer v0.3.0
[INFO] [stderr]   Downloaded futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded async-coap-uri-macros v0.1.0
[INFO] [stderr]   Downloaded futures-executor-preview v0.3.0-alpha.18
[INFO] [stderr]   Downloaded async-coap-uri v0.1.0
[INFO] [stderr]   Downloaded futures-util-preview v0.3.0-alpha.18
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7e2754e2a25e74800408bf801c36515571b4ee8f80b22352a07e9f21b5c917cb
[INFO] running `Command { std: "docker" "start" "-a" "7e2754e2a25e74800408bf801c36515571b4ee8f80b22352a07e9f21b5c917cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7e2754e2a25e74800408bf801c36515571b4ee8f80b22352a07e9f21b5c917cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7e2754e2a25e74800408bf801c36515571b4ee8f80b22352a07e9f21b5c917cb", kill_on_drop: false }`
[INFO] [stdout] 7e2754e2a25e74800408bf801c36515571b4ee8f80b22352a07e9f21b5c917cb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e966ac8d8bb4f3aa524cefaeac858c872bc89e6692218f7254ddba1f4516ea26
[INFO] running `Command { std: "docker" "start" "-a" "e966ac8d8bb4f3aa524cefaeac858c872bc89e6692218f7254ddba1f4516ea26", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling autocfg v0.1.8
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling aho-corasick v1.1.4
[INFO] [stderr]     Checking futures-io-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking num_cpus v1.17.0
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]     Checking num-iter v0.1.45
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[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]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]     Checking num v0.2.1
[INFO] [stderr]    Compiling regex-automata v0.4.14
[INFO] [stderr]    Compiling regex v1.12.3
[INFO] [stderr]    Compiling futures-join-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling futures-select-macro-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling async-coap-uri-macros v0.1.0
[INFO] [stderr]     Checking 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/index.crates.io-1949cf8c6b5b557f/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]   |                                      ^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[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] [stderr]     Checking async-coap-uri v0.1.0
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `futures-util-preview` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "e966ac8d8bb4f3aa524cefaeac858c872bc89e6692218f7254ddba1f4516ea26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e966ac8d8bb4f3aa524cefaeac858c872bc89e6692218f7254ddba1f4516ea26", kill_on_drop: false }`
[INFO] [stdout] e966ac8d8bb4f3aa524cefaeac858c872bc89e6692218f7254ddba1f4516ea26