[INFO] fetching crate pngenc 0.1.0...
[INFO] building pngenc-0.1.0 against master#c7f6aa2869acdbf014d094c6e427e554e160b6db for pr-146237-2
[INFO] extracting crate pngenc 0.1.0 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate pngenc 0.1.0
[INFO] finished tweaking crates.io crate pngenc 0.1.0
[INFO] tweaked toml for crates.io crate pngenc 0.1.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate pngenc 0.1.0 on toolchain c7f6aa2869acdbf014d094c6e427e554e160b6db
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "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" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 13 packages to latest compatible versions
[INFO] [stderr]       Adding png v0.17.16 (available: v0.18.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded crc32c v0.6.8
[INFO] [stderr]   Downloaded atools v0.1.7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6a2d789cfab486515e94776b0b7fe4cc104e5396d769f484f8d52f18aab90974
[INFO] running `Command { std: "docker" "start" "-a" "6a2d789cfab486515e94776b0b7fe4cc104e5396d769f484f8d52f18aab90974", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6a2d789cfab486515e94776b0b7fe4cc104e5396d769f484f8d52f18aab90974", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6a2d789cfab486515e94776b0b7fe4cc104e5396d769f484f8d52f18aab90974", kill_on_drop: false }`
[INFO] [stdout] 6a2d789cfab486515e94776b0b7fe4cc104e5396d769f484f8d52f18aab90974
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 22cec07aa1173d425bbf5d690ef40aefd94e849f8477b6726e33adb1ba5c75d7
[INFO] running `Command { std: "docker" "start" "-a" "22cec07aa1173d425bbf5d690ef40aefd94e849f8477b6726e33adb1ba5c75d7", kill_on_drop: false }`
[INFO] [stderr]    Compiling crc32c v0.6.8
[INFO] [stderr]    Compiling crc32fast v1.5.0
[INFO] [stderr]    Compiling atools v0.1.7
[INFO] [stderr]    Compiling simd-adler32 v0.3.7
[INFO] [stderr]    Compiling pngenc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `slice_as_chunks` has been stable since 1.88.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:16:39
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(generic_const_exprs, test, slice_as_chunks, array_chunks)]
[INFO] [stdout]    |                                       ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `array_chunks`
[INFO] [stdout]   --> src/lib.rs:16:56
[INFO] [stdout]    |
[INFO] [stdout] 16 | #![feature(generic_const_exprs, test, slice_as_chunks, array_chunks)]
[INFO] [stdout]    |                                                        ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `pngenc` (lib) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "22cec07aa1173d425bbf5d690ef40aefd94e849f8477b6726e33adb1ba5c75d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22cec07aa1173d425bbf5d690ef40aefd94e849f8477b6726e33adb1ba5c75d7", kill_on_drop: false }`
[INFO] [stdout] 22cec07aa1173d425bbf5d690ef40aefd94e849f8477b6726e33adb1ba5c75d7