[INFO] cloning repository https://github.com/dadikovi/minchain
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dadikovi/minchain" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdadikovi%2Fminchain", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdadikovi%2Fminchain'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bc05e97974f8ff5e3993e9bf96a5762c8364e9fb
[INFO] checking dadikovi/minchain against master#385fa9d845dd326c6bbfd58c22244215e431948a for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdadikovi%2Fminchain" "/workspace/builds/worker-6-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dadikovi/minchain 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/dadikovi/minchain
[INFO] finished tweaking git repo https://github.com/dadikovi/minchain
[INFO] tweaked toml for git repo https://github.com/dadikovi/minchain written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/dadikovi/minchain 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 45175bf1f5ebd570b800ad89e0a5399b1a96d2e70ea937f71e39c1c17d2c3249
[INFO] running `Command { std: "docker" "start" "-a" "45175bf1f5ebd570b800ad89e0a5399b1a96d2e70ea937f71e39c1c17d2c3249", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "45175bf1f5ebd570b800ad89e0a5399b1a96d2e70ea937f71e39c1c17d2c3249", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "45175bf1f5ebd570b800ad89e0a5399b1a96d2e70ea937f71e39c1c17d2c3249", kill_on_drop: false }`
[INFO] [stdout] 45175bf1f5ebd570b800ad89e0a5399b1a96d2e70ea937f71e39c1c17d2c3249
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 2a041cf038a3db52169b253a89a8a7e220855b43daff6b44fb39e0fc6585bc5d
[INFO] running `Command { std: "docker" "start" "-a" "2a041cf038a3db52169b253a89a8a7e220855b43daff6b44fb39e0fc6585bc5d", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.118
[INFO] [stderr]    Compiling typenum v1.15.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.7
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]     Checking itoa v1.0.1
[INFO] [stderr]     Checking cpufeatures v0.2.1
[INFO] [stderr]     Checking ryu v1.0.9
[INFO] [stderr]     Checking json v0.12.4
[INFO] [stderr]     Checking crossbeam v0.3.2
[INFO] [stderr]    Compiling generic-array v0.14.5
[INFO] [stderr]     Checking crossbeam-channel v0.5.2
[INFO] [stderr]     Checking getrandom v0.2.4
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking colored v2.0.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking crypto-common v0.1.3
[INFO] [stderr]     Checking block-buffer v0.10.2
[INFO] [stderr]     Checking digest v0.10.3
[INFO] [stderr]     Checking sha2 v0.10.2
[INFO] [stderr]     Checking minchain v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/chain.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |         valid_chain.add_genesis();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 98 |         let _ = valid_chain.add_genesis();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/chain.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |         valid_chain.add_content(String::from("hello-world"));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 99 |         let _ = valid_chain.add_content(String::from("hello-world"));
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 6.73s
[INFO] running `Command { std: "docker" "inspect" "2a041cf038a3db52169b253a89a8a7e220855b43daff6b44fb39e0fc6585bc5d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a041cf038a3db52169b253a89a8a7e220855b43daff6b44fb39e0fc6585bc5d", kill_on_drop: false }`
[INFO] [stdout] 2a041cf038a3db52169b253a89a8a7e220855b43daff6b44fb39e0fc6585bc5d
[INFO] checking dadikovi/minchain against try#645bb72776a6a56a1a8f52631a44bd082b2ba509 for absurd-question-mark-desugar
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdadikovi%2Fminchain" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dadikovi/minchain on toolchain 645bb72776a6a56a1a8f52631a44bd082b2ba509
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dadikovi/minchain
[INFO] finished tweaking git repo https://github.com/dadikovi/minchain
[INFO] tweaked toml for git repo https://github.com/dadikovi/minchain written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/dadikovi/minchain 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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fca0bc957b49165cceec4cddf74e494c7640987e8338497a51df9bf7dc3787b6
[INFO] running `Command { std: "docker" "start" "-a" "fca0bc957b49165cceec4cddf74e494c7640987e8338497a51df9bf7dc3787b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fca0bc957b49165cceec4cddf74e494c7640987e8338497a51df9bf7dc3787b6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fca0bc957b49165cceec4cddf74e494c7640987e8338497a51df9bf7dc3787b6", kill_on_drop: false }`
[INFO] [stdout] fca0bc957b49165cceec4cddf74e494c7640987e8338497a51df9bf7dc3787b6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "+645bb72776a6a56a1a8f52631a44bd082b2ba509" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 297721c90f1646c4dcc13766626f7e2ec463415da0715546797ccf0957ec1bc3
[INFO] running `Command { std: "docker" "start" "-a" "297721c90f1646c4dcc13766626f7e2ec463415da0715546797ccf0957ec1bc3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.118
[INFO] [stderr]    Compiling typenum v1.15.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.7
[INFO] [stderr]    Compiling serde v1.0.136
[INFO] [stderr]    Compiling serde_json v1.0.79
[INFO] [stderr]     Checking ppv-lite86 v0.2.16
[INFO] [stderr]     Checking ryu v1.0.9
[INFO] [stderr]     Checking cpufeatures v0.2.1
[INFO] [stderr]     Checking itoa v1.0.1
[INFO] [stderr]     Checking crossbeam v0.3.2
[INFO] [stderr]     Checking json v0.12.4
[INFO] [stderr]    Compiling generic-array v0.14.5
[INFO] [stderr]     Checking crossbeam-channel v0.5.2
[INFO] [stderr]     Checking getrandom v0.2.4
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking colored v2.0.0
[INFO] [stderr]     Checking rand_core v0.6.3
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking crypto-common v0.1.3
[INFO] [stderr]     Checking block-buffer v0.10.2
[INFO] [stderr]     Checking digest v0.10.3
[INFO] [stderr]     Checking sha2 v0.10.2
[INFO] [stderr]     Checking minchain v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/chain.rs:98:9
[INFO] [stdout]    |
[INFO] [stdout] 98 |         valid_chain.add_genesis();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 98 |         let _ = valid_chain.add_genesis();
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/chain.rs:99:9
[INFO] [stdout]    |
[INFO] [stdout] 99 |         valid_chain.add_content(String::from("hello-world"));
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 99 |         let _ = valid_chain.add_content(String::from("hello-world"));
[INFO] [stdout]    |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 8.11s
[INFO] running `Command { std: "docker" "inspect" "297721c90f1646c4dcc13766626f7e2ec463415da0715546797ccf0957ec1bc3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "297721c90f1646c4dcc13766626f7e2ec463415da0715546797ccf0957ec1bc3", kill_on_drop: false }`
[INFO] [stdout] 297721c90f1646c4dcc13766626f7e2ec463415da0715546797ccf0957ec1bc3