[INFO] fetching crate fuzzmutator 0.2.1...
[INFO] checking fuzzmutator-0.2.1 against master#31ee872db5aae4750e3da1ca4ed1523c4356947f for pr-78461
[INFO] extracting crate fuzzmutator 0.2.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate fuzzmutator 0.2.1 on toolchain 31ee872db5aae4750e3da1ca4ed1523c4356947f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate fuzzmutator 0.2.1
[INFO] finished tweaking crates.io crate fuzzmutator 0.2.1
[INFO] tweaked toml for crates.io crate fuzzmutator 0.2.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7a068a2dcff14e40198b1374d613a3c38cbfa548ce2556c07d824b0b30bd6bd4
[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" "7a068a2dcff14e40198b1374d613a3c38cbfa548ce2556c07d824b0b30bd6bd4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7a068a2dcff14e40198b1374d613a3c38cbfa548ce2556c07d824b0b30bd6bd4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7a068a2dcff14e40198b1374d613a3c38cbfa548ce2556c07d824b0b30bd6bd4", kill_on_drop: false }`
[INFO] [stdout] 7a068a2dcff14e40198b1374d613a3c38cbfa548ce2556c07d824b0b30bd6bd4
[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=forbid" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+31ee872db5aae4750e3da1ca4ed1523c4356947f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7d6d02573255790c27a691e958e1c3ade4b4e4adbcef035a9e4a2fa7e5fab3bb
[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" "7d6d02573255790c27a691e958e1c3ade4b4e4adbcef035a9e4a2fa7e5fab3bb", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.80
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking fuzzmutator v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: no method named `mutation_grade` found for struct `MutatorEngine` in the current scope
[INFO] [stdout]    --> src/mutator.rs:389:19
[INFO] [stdout]     |
[INFO] [stdout] 28  | pub struct MutatorEngine {
[INFO] [stdout]     | ------------------------ method `mutation_grade` not found for this
[INFO] [stdout] ...
[INFO] [stdout] 389 |         mutatoren.mutation_grade(0.199);
[INFO] [stdout]     |                   ^^^^^^^^^^^^^^ method not found in `MutatorEngine`
[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 E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `fuzzmutator`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "7d6d02573255790c27a691e958e1c3ade4b4e4adbcef035a9e4a2fa7e5fab3bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7d6d02573255790c27a691e958e1c3ade4b4e4adbcef035a9e4a2fa7e5fab3bb", kill_on_drop: false }`
[INFO] [stdout] 7d6d02573255790c27a691e958e1c3ade4b4e4adbcef035a9e4a2fa7e5fab3bb