[INFO] cloning repository https://github.com/Jannikio/merkle_tree
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Jannikio/merkle_tree" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJannikio%2Fmerkle_tree", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJannikio%2Fmerkle_tree'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 7e931c6c940d69b676b18a86de29edc5a84e2cba
[INFO] checking Jannikio/merkle_tree/7e931c6c940d69b676b18a86de29edc5a84e2cba against master#5ad98b4026d5172f27615b105658bc8bfd677be8 for pr-129422
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJannikio%2Fmerkle_tree" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Jannikio/merkle_tree on toolchain 5ad98b4026d5172f27615b105658bc8bfd677be8
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+5ad98b4026d5172f27615b105658bc8bfd677be8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Jannikio/merkle_tree
[INFO] finished tweaking git repo https://github.com/Jannikio/merkle_tree
[INFO] tweaked toml for git repo https://github.com/Jannikio/merkle_tree written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/Jannikio/merkle_tree 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" "+5ad98b4026d5172f27615b105658bc8bfd677be8" "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-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+5ad98b4026d5172f27615b105658bc8bfd677be8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fbacfd3d6cee9be5a527a2aa37456d530d1ca9f48579edb7d4ad83d7552b5bab
[INFO] running `Command { std: "docker" "start" "-a" "fbacfd3d6cee9be5a527a2aa37456d530d1ca9f48579edb7d4ad83d7552b5bab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fbacfd3d6cee9be5a527a2aa37456d530d1ca9f48579edb7d4ad83d7552b5bab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fbacfd3d6cee9be5a527a2aa37456d530d1ca9f48579edb7d4ad83d7552b5bab", kill_on_drop: false }`
[INFO] [stdout] fbacfd3d6cee9be5a527a2aa37456d530d1ca9f48579edb7d4ad83d7552b5bab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:923055f121b5182466d55868a8b05e67af8ba4a3a3f6bad814e953ca3cd3ac2a" "/opt/rustwide/cargo-home/bin/cargo" "+5ad98b4026d5172f27615b105658bc8bfd677be8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] fc82a42a3d2a6dc207281b4f9cac3d934e68a194479e25bb0b2896eaa3a4e639
[INFO] running `Command { std: "docker" "start" "-a" "fc82a42a3d2a6dc207281b4f9cac3d934e68a194479e25bb0b2896eaa3a4e639", kill_on_drop: false }`
[INFO] [stderr]     Checking cpufeatures v0.2.5
[INFO] [stderr]     Checking hex v0.3.2
[INFO] [stderr]     Checking block-buffer v0.10.3
[INFO] [stderr]     Checking digest v0.10.6
[INFO] [stderr]     Checking sha2 v0.10.6
[INFO] [stderr]     Checking merkle_tree v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]    --> src/tree.rs:198:32
[INFO] [stdout]     |
[INFO] [stdout] 198 |             for nodes_stage in nodes_opening {
[INFO] [stdout]     |                                ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to check pattern in a loop use `while let`
[INFO] [stdout]     |
[INFO] [stdout] 198 |             while let Some(nodes_stage) = nodes_opening {
[INFO] [stdout]     |             ~~~~~~~~~~~~~~~           ~~~
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]     |
[INFO] [stdout] 198 |             if let Some(nodes_stage) = nodes_opening {
[INFO] [stdout]     |             ~~~~~~~~~~~~           ~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]    --> src/tree.rs:198:32
[INFO] [stdout]     |
[INFO] [stdout] 198 |             for nodes_stage in nodes_opening {
[INFO] [stdout]     |                                ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to check pattern in a loop use `while let`
[INFO] [stdout]     |
[INFO] [stdout] 198 |             while let Some(nodes_stage) = nodes_opening {
[INFO] [stdout]     |             ~~~~~~~~~~~~~~~           ~~~
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]     |
[INFO] [stdout] 198 |             if let Some(nodes_stage) = nodes_opening {
[INFO] [stdout]     |             ~~~~~~~~~~~~           ~~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.81s
[INFO] running `Command { std: "docker" "inspect" "fc82a42a3d2a6dc207281b4f9cac3d934e68a194479e25bb0b2896eaa3a4e639", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc82a42a3d2a6dc207281b4f9cac3d934e68a194479e25bb0b2896eaa3a4e639", kill_on_drop: false }`
[INFO] [stdout] fc82a42a3d2a6dc207281b4f9cac3d934e68a194479e25bb0b2896eaa3a4e639