[INFO] fetching crate watchcraft 0.0.1...
[INFO] testing watchcraft-0.0.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate watchcraft 0.0.1 into /workspace/builds/worker-7-tc1/source
[INFO] started tweaking crates.io crate watchcraft 0.0.1
[INFO] finished tweaking crates.io crate watchcraft 0.0.1
[INFO] tweaked toml for crates.io crate watchcraft 0.0.1 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate watchcraft 0.0.1 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] crate crates.io crate watchcraft 0.0.1 already has a lockfile, it will not be regenerated
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 4e5dae6412aa41138d73d91d3a25beb47d8f706ef52f5f81210ceb6d34a01d81
[INFO] running `Command { std: "docker" "start" "-a" "4e5dae6412aa41138d73d91d3a25beb47d8f706ef52f5f81210ceb6d34a01d81", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4e5dae6412aa41138d73d91d3a25beb47d8f706ef52f5f81210ceb6d34a01d81", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e5dae6412aa41138d73d91d3a25beb47d8f706ef52f5f81210ceb6d34a01d81", kill_on_drop: false }`
[INFO] [stdout] 4e5dae6412aa41138d73d91d3a25beb47d8f706ef52f5f81210ceb6d34a01d81
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 8c6788d0c7ce50c6c75b22882c253e99ab88775ce6a0f95b41a588d7a5f2432e
[INFO] running `Command { std: "docker" "start" "-a" "8c6788d0c7ce50c6c75b22882c253e99ab88775ce6a0f95b41a588d7a5f2432e", kill_on_drop: false }`
[INFO] [stderr]    Compiling watchcraft v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(explicit_tail_calls)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `explicit_tail_calls` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(explicit_tail_calls)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: see issue #112788 <https://github.com/rust-lang/rust/issues/112788> for more information
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `watchcraft` (bin "watchcraft") due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "8c6788d0c7ce50c6c75b22882c253e99ab88775ce6a0f95b41a588d7a5f2432e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c6788d0c7ce50c6c75b22882c253e99ab88775ce6a0f95b41a588d7a5f2432e", kill_on_drop: false }`
[INFO] [stdout] 8c6788d0c7ce50c6c75b22882c253e99ab88775ce6a0f95b41a588d7a5f2432e