[INFO] fetching crate esp8266 0.6.0...
[INFO] testing esp8266-0.6.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate esp8266 0.6.0 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate esp8266 0.6.0
[INFO] finished tweaking crates.io crate esp8266 0.6.0
[INFO] tweaked toml for crates.io crate esp8266 0.6.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate esp8266 0.6.0 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 28 packages to latest compatible versions
[INFO] [stderr]       Adding xtensa-lx v0.7.0 (available: v0.12.0)
[INFO] [stderr]       Adding xtensa-lx-rt v0.11.0 (available: v0.20.0)
[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 mutex-trait v0.2.0
[INFO] [stderr]   Downloaded xtensa-lx v0.7.0
[INFO] [stderr]   Downloaded bare-metal v1.0.0
[INFO] [stderr]   Downloaded r0 v1.0.0
[INFO] [stderr]   Downloaded xtensa-lx-rt-proc-macros v0.1.0
[INFO] [stderr]   Downloaded enum-as-inner v0.4.0
[INFO] [stderr]   Downloaded minijinja v0.15.0
[INFO] [stderr]   Downloaded core-isa-parser v0.2.0
[INFO] [stderr]   Downloaded xtensa-lx-rt v0.11.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 40a7c3c88dde60fdadc32cf19d52f884824e108622b02faf0730c8e7329aa6e3
[INFO] running `Command { std: "docker" "start" "-a" "40a7c3c88dde60fdadc32cf19d52f884824e108622b02faf0730c8e7329aa6e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "40a7c3c88dde60fdadc32cf19d52f884824e108622b02faf0730c8e7329aa6e3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "40a7c3c88dde60fdadc32cf19d52f884824e108622b02faf0730c8e7329aa6e3", kill_on_drop: false }`
[INFO] [stdout] 40a7c3c88dde60fdadc32cf19d52f884824e108622b02faf0730c8e7329aa6e3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] f3c8d0cd25e9ebc58a2c4876009c3c81b95b255a45b083b49ab7c3d550c71340
[INFO] running `Command { std: "docker" "start" "-a" "f3c8d0cd25e9ebc58a2c4876009c3c81b95b255a45b083b49ab7c3d550c71340", kill_on_drop: false }`
[INFO] [stderr]    Compiling xtensa-lx v0.7.0
[INFO] [stderr]    Compiling bare-metal v1.0.0
[INFO] [stderr]    Compiling mutex-trait v0.2.0
[INFO] [stderr]    Compiling esp8266 v0.6.0 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling r0 v1.0.0
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/xtensa-lx-0.7.0/src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(asm_experimental_arch)]
[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 `xtensa-lx` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "f3c8d0cd25e9ebc58a2c4876009c3c81b95b255a45b083b49ab7c3d550c71340", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f3c8d0cd25e9ebc58a2c4876009c3c81b95b255a45b083b49ab7c3d550c71340", kill_on_drop: false }`
[INFO] [stdout] f3c8d0cd25e9ebc58a2c4876009c3c81b95b255a45b083b49ab7c3d550c71340