[INFO] cloning repository https://github.com/dwjackson/roll
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dwjackson/roll" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdwjackson%2Froll", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdwjackson%2Froll'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ab1c8910940eaf470683ac318118f336c7771ee5
[INFO] checking dwjackson/roll against master#385fa9d845dd326c6bbfd58c22244215e431948a for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdwjackson%2Froll" "/workspace/builds/worker-3-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dwjackson/roll on toolchain 385fa9d845dd326c6bbfd58c22244215e431948a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dwjackson/roll
[INFO] finished tweaking git repo https://github.com/dwjackson/roll
[INFO] tweaked toml for git repo https://github.com/dwjackson/roll written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/dwjackson/roll already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3a2990337151ebbc8b4d656550c40b65a57c26aeef043add94e229cacf24441a
[INFO] running `Command { std: "docker" "start" "-a" "3a2990337151ebbc8b4d656550c40b65a57c26aeef043add94e229cacf24441a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3a2990337151ebbc8b4d656550c40b65a57c26aeef043add94e229cacf24441a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3a2990337151ebbc8b4d656550c40b65a57c26aeef043add94e229cacf24441a", kill_on_drop: false }`
[INFO] [stdout] 3a2990337151ebbc8b4d656550c40b65a57c26aeef043add94e229cacf24441a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+385fa9d845dd326c6bbfd58c22244215e431948a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 31729dbce1b624e6fb0e45a98bffa75c58eec27ba5571a1086e4097c762b841f
[INFO] running `Command { std: "docker" "start" "-a" "31729dbce1b624e6fb0e45a98bffa75c58eec27ba5571a1086e4097c762b841f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.148
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]     Checking regex-syntax v0.6.21
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.15
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking regex v1.4.2
[INFO] [stderr]     Checking roll v0.2.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `ToString` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::string::ToString;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:144:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `ToString` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ToString` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::string::ToString;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/385fa9d845dd326c6bbfd58c22244215e431948a/library/std/src/prelude/mod.rs:144:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `ToString` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.76s
[INFO] running `Command { std: "docker" "inspect" "31729dbce1b624e6fb0e45a98bffa75c58eec27ba5571a1086e4097c762b841f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31729dbce1b624e6fb0e45a98bffa75c58eec27ba5571a1086e4097c762b841f", kill_on_drop: false }`
[INFO] [stdout] 31729dbce1b624e6fb0e45a98bffa75c58eec27ba5571a1086e4097c762b841f
[INFO] checking dwjackson/roll against try#2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2 for never-type-fallback-to-never
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdwjackson%2Froll" "/workspace/builds/worker-3-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dwjackson/roll on toolchain 2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dwjackson/roll
[INFO] finished tweaking git repo https://github.com/dwjackson/roll
[INFO] tweaked toml for git repo https://github.com/dwjackson/roll written to /workspace/builds/worker-3-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/dwjackson/roll already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b15147d93eb7badea7f1b5282d28535510ca16c05039ff3d974423dd037b0404
[INFO] running `Command { std: "docker" "start" "-a" "b15147d93eb7badea7f1b5282d28535510ca16c05039ff3d974423dd037b0404", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b15147d93eb7badea7f1b5282d28535510ca16c05039ff3d974423dd037b0404", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b15147d93eb7badea7f1b5282d28535510ca16c05039ff3d974423dd037b0404", kill_on_drop: false }`
[INFO] [stdout] b15147d93eb7badea7f1b5282d28535510ca16c05039ff3d974423dd037b0404
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc2/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 491f3425e3172b98d92a637a7d4a48f1c8ffe899d57371f3f52e4e8265b2380d
[INFO] running `Command { std: "docker" "start" "-a" "491f3425e3172b98d92a637a7d4a48f1c8ffe899d57371f3f52e4e8265b2380d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.148
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]     Checking regex-syntax v0.6.21
[INFO] [stderr]     Checking thread_local v1.0.1
[INFO] [stderr]     Checking aho-corasick v0.7.15
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking regex v1.4.2
[INFO] [stderr]     Checking roll v0.2.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `ToString` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::string::ToString;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2/library/std/src/prelude/mod.rs:144:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `ToString` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ToString` is imported redundantly
[INFO] [stdout]  --> src/lib.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::string::ToString;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]  --> /rustc/2d84f2737f3bd9ebfcb07f75aa198d6cf7c715d2/library/std/src/prelude/mod.rs:144:13
[INFO] [stdout]   |
[INFO] [stdout]   = note: the item `ToString` is already defined here
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 5.93s
[INFO] running `Command { std: "docker" "inspect" "491f3425e3172b98d92a637a7d4a48f1c8ffe899d57371f3f52e4e8265b2380d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "491f3425e3172b98d92a637a7d4a48f1c8ffe899d57371f3f52e4e8265b2380d", kill_on_drop: false }`
[INFO] [stdout] 491f3425e3172b98d92a637a7d4a48f1c8ffe899d57371f3f52e4e8265b2380d