[INFO] fetching crate nightfall 0.1.8...
[INFO] testing nightfall-0.1.8 against 1.54.0 for beta-1.55-1
[INFO] extracting crate nightfall 0.1.8 into /workspace/builds/worker-107/source
[INFO] validating manifest of crates.io crate nightfall 0.1.8 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nightfall 0.1.8
[INFO] finished tweaking crates.io crate nightfall 0.1.8
[INFO] tweaked toml for crates.io crate nightfall 0.1.8 written to /workspace/builds/worker-107/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", 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]  Downloading crates ...
[INFO] [stderr]   Downloaded spin v0.7.1
[INFO] [stderr]   Downloaded pollster v0.2.4
[INFO] [stderr]   Downloaded flume v0.10.8
[INFO] [stderr]   Downloaded psutil v3.2.1
[INFO] [stderr]   Downloaded darwin-libproc v0.1.2
[INFO] [stderr]   Downloaded unescape v0.1.0
[INFO] [stderr]   Downloaded err-derive v0.3.0
[INFO] [stderr]   Downloaded tokio-stream v0.1.7
[INFO] [stderr]   Downloaded generator v0.6.25
[INFO] [stderr]   Downloaded barrage v0.2.1
[INFO] [stderr]   Downloaded darwin-libproc-sys v0.1.2
[INFO] [stderr]   Downloaded xtra_proc v0.1.0
[INFO] [stderr]   Downloaded spinny v0.2.2
[INFO] [stderr]   Downloaded catty v0.1.4
[INFO] [stderr]   Downloaded slog v2.7.0
[INFO] [stderr]   Downloaded rustversion v1.0.5
[INFO] [stderr]   Downloaded xtra v0.5.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7645ece9fafbff9b9481f753943aee027f30b8087d516c74cc4d853ab57d5c50
[INFO] running `Command { std: "docker" "start" "-a" "7645ece9fafbff9b9481f753943aee027f30b8087d516c74cc4d853ab57d5c50", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7645ece9fafbff9b9481f753943aee027f30b8087d516c74cc4d853ab57d5c50", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7645ece9fafbff9b9481f753943aee027f30b8087d516c74cc4d853ab57d5c50", kill_on_drop: false }`
[INFO] [stdout] 7645ece9fafbff9b9481f753943aee027f30b8087d516c74cc4d853ab57d5c50
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e0609481ee1ebebec457e13e8b2dc312e7e9310b118fff8e8d9145fa1c556f72
[INFO] running `Command { std: "docker" "start" "-a" "e0609481ee1ebebec457e13e8b2dc312e7e9310b118fff8e8d9145fa1c556f72", 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 syn v1.0.74
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling rustversion v1.0.5
[INFO] [stderr]    Compiling nix v0.17.0
[INFO] [stderr]    Compiling serde v1.0.127
[INFO] [stderr]    Compiling once_cell v1.8.0
[INFO] [stderr]    Compiling futures-sink v0.3.16
[INFO] [stderr]    Compiling slog v2.7.0
[INFO] [stderr]    Compiling glob v0.3.0
[INFO] [stderr]    Compiling unescape v0.1.0
[INFO] [stderr]    Compiling platforms v0.2.1
[INFO] [stderr]    Compiling pollster v0.2.4
[INFO] [stderr]    Compiling futures-core v0.3.16
[INFO] [stderr]    Compiling futures-util v0.3.16
[INFO] [stderr]    Compiling tokio v1.9.0
[INFO] [stderr]    Compiling catty v0.1.4
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling spinny v0.2.2
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling spinning_top v0.2.4
[INFO] [stderr]    Compiling barrage v0.2.1
[INFO] [stderr]    Compiling err-derive v0.3.0
[INFO] [stderr]    Compiling mio v0.7.13
[INFO] [stderr]    Compiling signal-hook-registry v1.4.0
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling nix v0.20.0
[INFO] [stderr]    Compiling uuid v0.8.2
[INFO] [stderr]    Compiling synstructure v0.12.5
[INFO] [stderr]    Compiling pin-project-internal v1.0.8
[INFO] [stderr]    Compiling serde_derive v1.0.127
[INFO] [stderr]    Compiling thiserror-impl v1.0.26
[INFO] [stderr]    Compiling tokio-macros v1.3.0
[INFO] [stderr]    Compiling futures-macro v0.3.16
[INFO] [stderr]    Compiling derive_more v0.99.16
[INFO] [stderr]    Compiling async-trait v0.1.51
[INFO] [stderr]    Compiling xtra_proc v0.1.0
[INFO] [stderr]    Compiling thiserror v1.0.26
[INFO] [stderr]    Compiling psutil v3.2.1
[INFO] [stderr]    Compiling pin-project v1.0.8
[INFO] [stderr]    Compiling flume v0.10.8
[INFO] [stderr]    Compiling xtra v0.5.1
[INFO] [stderr]    Compiling tokio-stream v0.1.7
[INFO] [stderr]    Compiling serde_json v1.0.66
[INFO] [stderr]    Compiling nightfall v0.1.8 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(assert_matches, result_flattening, hash_drain_filter)]
[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 `nightfall`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "e0609481ee1ebebec457e13e8b2dc312e7e9310b118fff8e8d9145fa1c556f72", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0609481ee1ebebec457e13e8b2dc312e7e9310b118fff8e8d9145fa1c556f72", kill_on_drop: false }`
[INFO] [stdout] e0609481ee1ebebec457e13e8b2dc312e7e9310b118fff8e8d9145fa1c556f72
