[INFO] cloning repository https://github.com/tuzz/supermutation
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tuzz/supermutation" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuzz%2Fsupermutation", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuzz%2Fsupermutation'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] eafbd87c5cb2e3c1926035910f6f21323a976f03
[INFO] testing tuzz/supermutation against 1.54.0 for beta-1.55-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftuzz%2Fsupermutation" "/workspace/builds/worker-38/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-38/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tuzz/supermutation on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tuzz/supermutation
[INFO] finished tweaking git repo https://github.com/tuzz/supermutation
[INFO] tweaked toml for git repo https://github.com/tuzz/supermutation written to /workspace/builds/worker-38/source/Cargo.toml
[INFO] crate git repo https://github.com/tuzz/supermutation already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--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-38/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8620d7eb8729a0961a64796793de0ae16a30f761b3b3df4c3149187c325b298d
[INFO] running `Command { std: "docker" "start" "-a" "8620d7eb8729a0961a64796793de0ae16a30f761b3b3df4c3149187c325b298d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8620d7eb8729a0961a64796793de0ae16a30f761b3b3df4c3149187c325b298d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8620d7eb8729a0961a64796793de0ae16a30f761b3b3df4c3149187c325b298d", kill_on_drop: false }`
[INFO] [stdout] 8620d7eb8729a0961a64796793de0ae16a30f761b3b3df4c3149187c325b298d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-38/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 54add7a9869712d44cf8be86e86683b2f4f31d401a511314b6ab286e0cb8671a
[INFO] running `Command { std: "docker" "start" "-a" "54add7a9869712d44cf8be86e86683b2f4f31d401a511314b6ab286e0cb8671a", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.44
[INFO] [stderr]    Compiling cfg-if v0.1.6
[INFO] [stderr]    Compiling glob v0.2.11
[INFO] [stderr]    Compiling cc v1.0.25
[INFO] [stderr]    Compiling lazy_static v1.2.0
[INFO] [stderr]    Compiling regex v1.0.6
[INFO] [stderr]    Compiling bindgen v0.37.4
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling lehmer v3.0.0
[INFO] [stderr]    Compiling bucket_queue v2.0.0
[INFO] [stderr]    Compiling memchr v2.1.1
[INFO] [stderr]    Compiling regex-syntax v0.6.3
[INFO] [stderr]    Compiling proc-macro2 v0.3.5
[INFO] [stderr]    Compiling log v0.4.6
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling clang-sys v0.23.0
[INFO] [stderr]    Compiling libloading v0.5.0
[INFO] [stderr]    Compiling atty v0.2.11
[INFO] [stderr]    Compiling memchr v1.0.2
[INFO] [stderr]    Compiling which v1.0.5
[INFO] [stderr]    Compiling clap v2.32.0
[INFO] [stderr]    Compiling nom v3.2.1
[INFO] [stderr]    Compiling aho-corasick v0.6.9
[INFO] [stderr]    Compiling cexpr v0.2.3
[INFO] [stderr]    Compiling env_logger v0.5.13
[INFO] [stderr]    Compiling croaring-sys v0.3.7
[INFO] [stderr]    Compiling croaring v0.3.7
[INFO] [stderr]    Compiling supermutation 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(uniform_paths)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `uniform_paths` has been stable since 1.32.0 and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `supermutation`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "54add7a9869712d44cf8be86e86683b2f4f31d401a511314b6ab286e0cb8671a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54add7a9869712d44cf8be86e86683b2f4f31d401a511314b6ab286e0cb8671a", kill_on_drop: false }`
[INFO] [stdout] 54add7a9869712d44cf8be86e86683b2f4f31d401a511314b6ab286e0cb8671a
