[INFO] fetching crate rifgen 0.1.51...
[INFO] testing rifgen-0.1.51 against 1.59.0 for beta-1.60-1
[INFO] extracting crate rifgen 0.1.51 into /workspace/builds/worker-62/source
[INFO] validating manifest of crates.io crate rifgen 0.1.51 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rifgen 0.1.51
[INFO] finished tweaking crates.io crate rifgen 0.1.51
[INFO] tweaked toml for crates.io crate rifgen 0.1.51 written to /workspace/builds/worker-62/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "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-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f64aca6232566f54cc08822bdd12fec2d9489f75ceab26371d206fbf004a9e5a
[INFO] running `Command { std: "docker" "start" "-a" "f64aca6232566f54cc08822bdd12fec2d9489f75ceab26371d206fbf004a9e5a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f64aca6232566f54cc08822bdd12fec2d9489f75ceab26371d206fbf004a9e5a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f64aca6232566f54cc08822bdd12fec2d9489f75ceab26371d206fbf004a9e5a", kill_on_drop: false }`
[INFO] [stdout] f64aca6232566f54cc08822bdd12fec2d9489f75ceab26371d206fbf004a9e5a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-62/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0569a096c36e75c81fe0aef1241548706766ef152cd54b7e2a0627e553c12633
[INFO] running `Command { std: "docker" "start" "-a" "0569a096c36e75c81fe0aef1241548706766ef152cd54b7e2a0627e553c12633", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling Inflector v0.11.4
[INFO] [stderr]    Compiling derive-new v0.5.9
[INFO] [stderr]    Compiling rifgen_attr v0.1.0
[INFO] [stderr]    Compiling rifgen v0.1.51 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(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 `rifgen` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "0569a096c36e75c81fe0aef1241548706766ef152cd54b7e2a0627e553c12633", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0569a096c36e75c81fe0aef1241548706766ef152cd54b7e2a0627e553c12633", kill_on_drop: false }`
[INFO] [stdout] 0569a096c36e75c81fe0aef1241548706766ef152cd54b7e2a0627e553c12633