[INFO] fetching crate panic-custom 0.1.1...
[INFO] testing panic-custom-0.1.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate panic-custom 0.1.1 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate panic-custom 0.1.1
[INFO] finished tweaking crates.io crate panic-custom 0.1.1
[INFO] tweaked toml for crates.io crate panic-custom 0.1.1 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate panic-custom 0.1.1 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "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" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 5 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded panic-custom-proc-macros v0.1.0
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f90195159dfa6121775b029dc9cdd1d2c94417af59b60447117fc46d20ea969a
[INFO] running `Command { std: "docker" "start" "-a" "f90195159dfa6121775b029dc9cdd1d2c94417af59b60447117fc46d20ea969a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f90195159dfa6121775b029dc9cdd1d2c94417af59b60447117fc46d20ea969a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f90195159dfa6121775b029dc9cdd1d2c94417af59b60447117fc46d20ea969a", kill_on_drop: false }`
[INFO] [stdout] f90195159dfa6121775b029dc9cdd1d2c94417af59b60447117fc46d20ea969a
[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=warn" "-e" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d1e4f973acdeac46f0fd1ace352adb35f17d4ecb0c25f5b1432aab8ef15d8c1c
[INFO] running `Command { std: "docker" "start" "-a" "d1e4f973acdeac46f0fd1ace352adb35f17d4ecb0c25f5b1432aab8ef15d8c1c", kill_on_drop: false }`
[INFO] [stderr]    Compiling panic-custom v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(used_with_arg, core_intrinsics, linkage, tuple_trait, doc_cfg)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `panic-custom` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "d1e4f973acdeac46f0fd1ace352adb35f17d4ecb0c25f5b1432aab8ef15d8c1c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d1e4f973acdeac46f0fd1ace352adb35f17d4ecb0c25f5b1432aab8ef15d8c1c", kill_on_drop: false }`
[INFO] [stdout] d1e4f973acdeac46f0fd1ace352adb35f17d4ecb0c25f5b1432aab8ef15d8c1c