[INFO] fetching crate my-first-crate 0.1.0...
[INFO] testing my-first-crate-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate my-first-crate 0.1.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate my-first-crate 0.1.0 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate my-first-crate 0.1.0
[INFO] finished tweaking crates.io crate my-first-crate 0.1.0
[INFO] tweaked toml for crates.io crate my-first-crate 0.1.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate crates.io crate my-first-crate 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3a7eed8710285700626ea135a48e4e2c587b98e59dae03285c9d0025e98d5c1d
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3a7eed8710285700626ea135a48e4e2c587b98e59dae03285c9d0025e98d5c1d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3a7eed8710285700626ea135a48e4e2c587b98e59dae03285c9d0025e98d5c1d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a7eed8710285700626ea135a48e4e2c587b98e59dae03285c9d0025e98d5c1d", kill_on_drop: false }`
[INFO] [stdout] 3a7eed8710285700626ea135a48e4e2c587b98e59dae03285c9d0025e98d5c1d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6b6c2a4d5fb373cea293cad02d48c3f0faf6d68c8345695bc5202f9ddd023bf2
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "6b6c2a4d5fb373cea293cad02d48c3f0faf6d68c8345695bc5202f9ddd023bf2", kill_on_drop: false }`
[INFO] [stderr]    Compiling bitflags v1.2.0
[INFO] [stderr]    Compiling literalext v0.1.1
[INFO] [stderr]    Compiling maud_htmlescape v0.17.0
[INFO] [stderr]    Compiling pulldown-cmark v0.4.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/literalext-0.1.1/src/lib.rs:19:37
[INFO] [stdout]    |
[INFO] [stdout] 19 | #![cfg_attr(feature = "proc-macro", feature(proc_macro))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `literalext`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "6b6c2a4d5fb373cea293cad02d48c3f0faf6d68c8345695bc5202f9ddd023bf2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b6c2a4d5fb373cea293cad02d48c3f0faf6d68c8345695bc5202f9ddd023bf2", kill_on_drop: false }`
[INFO] [stdout] 6b6c2a4d5fb373cea293cad02d48c3f0faf6d68c8345695bc5202f9ddd023bf2