[INFO] fetching crate lark-string 0.1.0...
[INFO] checking lark-string-0.1.0 against try#cac44d9528e3bbbdaa1537d187bd489ccc5de18c for pr-91141
[INFO] extracting crate lark-string 0.1.0 into /workspace/builds/worker-30/source
[INFO] validating manifest of crates.io crate lark-string 0.1.0 on toolchain cac44d9528e3bbbdaa1537d187bd489ccc5de18c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate lark-string 0.1.0
[INFO] finished tweaking crates.io crate lark-string 0.1.0
[INFO] tweaked toml for crates.io crate lark-string 0.1.0 written to /workspace/builds/worker-30/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "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" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-30/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-30/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ea4ce49d935f5e30487a4ff04d6414bbbcd175a9124c15fb5512474adf4f7479
[INFO] running `Command { std: "docker" "start" "-a" "ea4ce49d935f5e30487a4ff04d6414bbbcd175a9124c15fb5512474adf4f7479", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ea4ce49d935f5e30487a4ff04d6414bbbcd175a9124c15fb5512474adf4f7479", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea4ce49d935f5e30487a4ff04d6414bbbcd175a9124c15fb5512474adf4f7479", kill_on_drop: false }`
[INFO] [stdout] ea4ce49d935f5e30487a4ff04d6414bbbcd175a9124c15fb5512474adf4f7479
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-30/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-30/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" "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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+cac44d9528e3bbbdaa1537d187bd489ccc5de18c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2cc092095977a8fedc2d3ad19fbf24d75c1b83feb8e52ba458f07cb356245dd7
[INFO] running `Command { std: "docker" "start" "-a" "2cc092095977a8fedc2d3ad19fbf24d75c1b83feb8e52ba458f07cb356245dd7", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]     Checking rustc-hash v1.1.0
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]     Checking lark-debug-with v0.1.0
[INFO] [stderr]     Checking owning_ref v0.4.1
[INFO] [stderr]     Checking lark-collections v0.1.0
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]     Checking lock_api v0.1.5
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[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]     Checking parking_lot v0.7.1
[INFO] [stderr]     Checking lark-intern v0.1.0
[INFO] [stderr]     Checking lark-string v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lark-string` due to 2 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "2cc092095977a8fedc2d3ad19fbf24d75c1b83feb8e52ba458f07cb356245dd7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2cc092095977a8fedc2d3ad19fbf24d75c1b83feb8e52ba458f07cb356245dd7", kill_on_drop: false }`
[INFO] [stdout] 2cc092095977a8fedc2d3ad19fbf24d75c1b83feb8e52ba458f07cb356245dd7