[INFO] fetching crate mango-test 0.2.1...
[INFO] testing mango-test-0.2.1 against 1.91.0 for beta-1.92-2
[INFO] extracting crate mango-test 0.2.1 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate mango-test 0.2.1
[INFO] finished tweaking crates.io crate mango-test 0.2.1
[INFO] tweaked toml for crates.io crate mango-test 0.2.1 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate mango-test 0.2.1 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "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" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 6 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded mango-core v0.2.1
[INFO] [stderr]   Downloaded qemu-exit v3.0.2
[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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7ad2e622561bb467ec0b77cfab02a8a23c52fe8545725af0fb5e3740f5fcdb6f
[INFO] running `Command { std: "docker" "start" "-a" "7ad2e622561bb467ec0b77cfab02a8a23c52fe8545725af0fb5e3740f5fcdb6f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7ad2e622561bb467ec0b77cfab02a8a23c52fe8545725af0fb5e3740f5fcdb6f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7ad2e622561bb467ec0b77cfab02a8a23c52fe8545725af0fb5e3740f5fcdb6f", kill_on_drop: false }`
[INFO] [stdout] 7ad2e622561bb467ec0b77cfab02a8a23c52fe8545725af0fb5e3740f5fcdb6f
[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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 15ee4628b5f8a18b0ecb6d2422736bd1666e71cc2fd14e3b3f2ea338e004c5fb
[INFO] running `Command { std: "docker" "start" "-a" "15ee4628b5f8a18b0ecb6d2422736bd1666e71cc2fd14e3b3f2ea338e004c5fb", kill_on_drop: false }`
[INFO] [stderr]    Compiling mango-core v0.2.1
[INFO] [stderr]    Compiling mango-test v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(custom_test_frameworks)]
[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 `mango-test` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "15ee4628b5f8a18b0ecb6d2422736bd1666e71cc2fd14e3b3f2ea338e004c5fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "15ee4628b5f8a18b0ecb6d2422736bd1666e71cc2fd14e3b3f2ea338e004c5fb", kill_on_drop: false }`
[INFO] [stdout] 15ee4628b5f8a18b0ecb6d2422736bd1666e71cc2fd14e3b3f2ea338e004c5fb