[INFO] fetching crate rofi-plugin 0.1.0...
[INFO] testing rofi-plugin-0.1.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate rofi-plugin 0.1.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate rofi-plugin 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 rofi-plugin 0.1.0
[INFO] finished tweaking crates.io crate rofi-plugin 0.1.0
[INFO] tweaked toml for crates.io crate rofi-plugin 0.1.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded syn-mid v0.5.2
[INFO] [stderr]   Downloaded terminated v1.0.0
[INFO] [stderr]   Downloaded genawaiter-proc-macro v0.99.1
[INFO] [stderr]   Downloaded real_c_string v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] 6ddbf4dc28fe0a084084e7d52d5d15917224bcade9c1257f2883fa78908e7252
[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" "6ddbf4dc28fe0a084084e7d52d5d15917224bcade9c1257f2883fa78908e7252", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6ddbf4dc28fe0a084084e7d52d5d15917224bcade9c1257f2883fa78908e7252", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6ddbf4dc28fe0a084084e7d52d5d15917224bcade9c1257f2883fa78908e7252", kill_on_drop: false }`
[INFO] [stdout] 6ddbf4dc28fe0a084084e7d52d5d15917224bcade9c1257f2883fa78908e7252
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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] c4ed9c22ace3ed9efffa6c66e1d85968c4ffbc28ed3b40aee950e132ddd51579
[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" "c4ed9c22ace3ed9efffa6c66e1d85968c4ffbc28ed3b40aee950e132ddd51579", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling genawaiter-macro v0.99.1
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling terminated v1.0.0
[INFO] [stderr]    Compiling proc-macro-error-attr v0.4.12
[INFO] [stderr]    Compiling proc-macro-error v0.4.12
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling real_c_string 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/real_c_string-0.1.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_hygiene)]
[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 `real_c_string`
[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" "c4ed9c22ace3ed9efffa6c66e1d85968c4ffbc28ed3b40aee950e132ddd51579", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c4ed9c22ace3ed9efffa6c66e1d85968c4ffbc28ed3b40aee950e132ddd51579", kill_on_drop: false }`
[INFO] [stdout] c4ed9c22ace3ed9efffa6c66e1d85968c4ffbc28ed3b40aee950e132ddd51579