[INFO] cloning repository https://github.com/lesurp/kaleidoscope
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/lesurp/kaleidoscope" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flesurp%2Fkaleidoscope", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flesurp%2Fkaleidoscope'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c9657c62c3190e3350016f1afcc7085f43d6cd90
[INFO] testing lesurp/kaleidoscope against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flesurp%2Fkaleidoscope" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/lesurp/kaleidoscope 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 git repo https://github.com/lesurp/kaleidoscope
[INFO] finished tweaking git repo https://github.com/lesurp/kaleidoscope
[INFO] tweaked toml for git repo https://github.com/lesurp/kaleidoscope written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/lesurp/kaleidoscope 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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] b2d7f525ebd451226fba9731cd2fbc4f39d83d2e5b1593763d1191144afcb7cc
[INFO] running `Command { std: "docker" "start" "-a" "b2d7f525ebd451226fba9731cd2fbc4f39d83d2e5b1593763d1191144afcb7cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b2d7f525ebd451226fba9731cd2fbc4f39d83d2e5b1593763d1191144afcb7cc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2d7f525ebd451226fba9731cd2fbc4f39d83d2e5b1593763d1191144afcb7cc", kill_on_drop: false }`
[INFO] [stdout] b2d7f525ebd451226fba9731cd2fbc4f39d83d2e5b1593763d1191144afcb7cc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] 655436df6331faa622369041cc7800a510b9a9bd7302611acf700ca7ea563fc0
[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" "655436df6331faa622369041cc7800a510b9a9bd7302611acf700ca7ea563fc0", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling regex-syntax v0.6.17
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]    Compiling ryu v1.0.3
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling version_check v0.9.1
[INFO] [stderr]    Compiling cc v1.0.54
[INFO] [stderr]    Compiling static_assertions v0.3.4
[INFO] [stderr]    Compiling quick-error v1.2.3
[INFO] [stderr]    Compiling termcolor v1.1.0
[INFO] [stderr]    Compiling lexical-core v0.6.7
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling nom v5.1.1
[INFO] [stderr]    Compiling aho-corasick v0.7.10
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling regex v1.3.7
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling llvm-sys v100.0.1
[INFO] [stderr]    Compiling kaleidoscope v0.1.0 (/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(generators, generator_trait)]
[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 `kaleidoscope`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "655436df6331faa622369041cc7800a510b9a9bd7302611acf700ca7ea563fc0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "655436df6331faa622369041cc7800a510b9a9bd7302611acf700ca7ea563fc0", kill_on_drop: false }`
[INFO] [stdout] 655436df6331faa622369041cc7800a510b9a9bd7302611acf700ca7ea563fc0