[INFO] fetching crate cargo-mutagen 0.1.2...
[INFO] checking cargo-mutagen-0.1.2 against try#6f8a6450478f69b8510c8976ab6c2a70b3b0e47c for pr-84920
[INFO] extracting crate cargo-mutagen 0.1.2 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate cargo-mutagen 0.1.2 on toolchain 6f8a6450478f69b8510c8976ab6c2a70b3b0e47c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate cargo-mutagen 0.1.2
[INFO] finished tweaking crates.io crate cargo-mutagen 0.1.2
[INFO] tweaked toml for crates.io crate cargo-mutagen 0.1.2 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded wait-timeout v0.1.5
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "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] db33bd43cd090dde37434ed0bb0aa7fe4c9f121f89156ca50d8f6182af805e97
[INFO] running `Command { std: "docker" "start" "-a" "db33bd43cd090dde37434ed0bb0aa7fe4c9f121f89156ca50d8f6182af805e97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "db33bd43cd090dde37434ed0bb0aa7fe4c9f121f89156ca50d8f6182af805e97", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "db33bd43cd090dde37434ed0bb0aa7fe4c9f121f89156ca50d8f6182af805e97", kill_on_drop: false }`
[INFO] [stdout] db33bd43cd090dde37434ed0bb0aa7fe4c9f121f89156ca50d8f6182af805e97
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 01e559da331da1d3b272a1d426ef7b2193f8e4a02ca46d5f3f3e03f6fbadbea4
[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" "01e559da331da1d3b272a1d426ef7b2193f8e4a02ca46d5f3f3e03f6fbadbea4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling cc v1.0.67
[INFO] [stderr]     Checking gimli v0.23.0
[INFO] [stderr]     Checking adler v1.0.2
[INFO] [stderr]     Checking object v0.23.0
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking rustc-demangle v0.1.19
[INFO] [stderr]     Checking json v0.11.15
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling backtrace v0.3.58
[INFO] [stderr]     Checking wait-timeout v0.1.5
[INFO] [stderr]     Checking addr2line v0.14.1
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]     Checking failure v0.1.8
[INFO] [stderr]     Checking cargo-mutagen v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/main.rs:48:31
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn run_mutations(runner: &mut Runner, list: &[String]) -> Result<()> {
[INFO] [stdout]    |                               ^^^^^^ help: use `dyn`: `dyn Runner`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/main.rs:161:26
[INFO] [stdout]     |
[INFO] [stdout] 161 |         let runner: &mut Runner = if with_coverage {
[INFO] [stdout]     |                          ^^^^^^ help: use `dyn`: `dyn Runner`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/main.rs:48:31
[INFO] [stdout]    |
[INFO] [stdout] 48 | fn run_mutations(runner: &mut Runner, list: &[String]) -> Result<()> {
[INFO] [stdout]    |                               ^^^^^^ help: use `dyn`: `dyn Runner`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/main.rs:161:26
[INFO] [stdout]     |
[INFO] [stdout] 161 |         let runner: &mut Runner = if with_coverage {
[INFO] [stdout]     |                          ^^^^^^ help: use `dyn`: `dyn Runner`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 11.63s
[INFO] running `Command { std: "docker" "inspect" "01e559da331da1d3b272a1d426ef7b2193f8e4a02ca46d5f3f3e03f6fbadbea4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "01e559da331da1d3b272a1d426ef7b2193f8e4a02ca46d5f3f3e03f6fbadbea4", kill_on_drop: false }`
[INFO] [stdout] 01e559da331da1d3b272a1d426ef7b2193f8e4a02ca46d5f3f3e03f6fbadbea4