[INFO] fetching crate markdown-renderer-that-you-probably-shouldnt-use 0.1.0...
[INFO] testing markdown-renderer-that-you-probably-shouldnt-use-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate markdown-renderer-that-you-probably-shouldnt-use 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate markdown-renderer-that-you-probably-shouldnt-use 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 markdown-renderer-that-you-probably-shouldnt-use 0.1.0
[INFO] finished tweaking crates.io crate markdown-renderer-that-you-probably-shouldnt-use 0.1.0
[INFO] tweaked toml for crates.io crate markdown-renderer-that-you-probably-shouldnt-use 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate markdown-renderer-that-you-probably-shouldnt-use 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9d18e63fd425f0da971eabbb22d7c13c7d5cb101dac5485caec7809b41fc8fcf
[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" "9d18e63fd425f0da971eabbb22d7c13c7d5cb101dac5485caec7809b41fc8fcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9d18e63fd425f0da971eabbb22d7c13c7d5cb101dac5485caec7809b41fc8fcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9d18e63fd425f0da971eabbb22d7c13c7d5cb101dac5485caec7809b41fc8fcf", kill_on_drop: false }`
[INFO] [stdout] 9d18e63fd425f0da971eabbb22d7c13c7d5cb101dac5485caec7809b41fc8fcf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 99a270e334c27c53a4d211b04cfd9e4effa72d60b3e52d035e19734485feafc3
[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" "99a270e334c27c53a4d211b04cfd9e4effa72d60b3e52d035e19734485feafc3", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling bitflags v1.2.0
[INFO] [stderr]    Compiling unicode-width v0.1.6
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling pulldown-cmark v0.4.1
[INFO] [stderr]    Compiling literalext v0.1.1
[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] [stderr]    Compiling getopts v0.2.21
[INFO] [stderr]    Compiling textwrap v0.11.0
[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" "99a270e334c27c53a4d211b04cfd9e4effa72d60b3e52d035e19734485feafc3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "99a270e334c27c53a4d211b04cfd9e4effa72d60b3e52d035e19734485feafc3", kill_on_drop: false }`
[INFO] [stdout] 99a270e334c27c53a4d211b04cfd9e4effa72d60b3e52d035e19734485feafc3