[INFO] fetching crate incrementalmerkletree-testing 0.2.0-backcompat.0.8...
[INFO] checking incrementalmerkletree-testing-0.2.0-backcompat.0.8 against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] extracting crate incrementalmerkletree-testing 0.2.0-backcompat.0.8 into /workspace/builds/worker-0-tc2/source
[INFO] started tweaking crates.io crate incrementalmerkletree-testing 0.2.0-backcompat.0.8
[INFO] finished tweaking crates.io crate incrementalmerkletree-testing 0.2.0-backcompat.0.8
[INFO] tweaked toml for crates.io crate incrementalmerkletree-testing 0.2.0-backcompat.0.8 written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate incrementalmerkletree-testing 0.2.0-backcompat.0.8 on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate incrementalmerkletree-testing 0.2.0-backcompat.0.8 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" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7079ab5dfb91d6a941e0098c8a22ba16e3fa6d3bab6b19c39812eaa980096de3
[INFO] running `Command { std: "docker" "start" "-a" "7079ab5dfb91d6a941e0098c8a22ba16e3fa6d3bab6b19c39812eaa980096de3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7079ab5dfb91d6a941e0098c8a22ba16e3fa6d3bab6b19c39812eaa980096de3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7079ab5dfb91d6a941e0098c8a22ba16e3fa6d3bab6b19c39812eaa980096de3", kill_on_drop: false }`
[INFO] [stdout] 7079ab5dfb91d6a941e0098c8a22ba16e3fa6d3bab6b19c39812eaa980096de3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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 -Dunmustuse_in_always_ok" "-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 78ab536bc09e3d47c4a4fa7917b8e0f84d85c3a9d05f2a98d93364333cb4d7c4
[INFO] running `Command { std: "docker" "start" "-a" "78ab536bc09e3d47c4a4fa7917b8e0f84d85c3a9d05f2a98d93364333cb4d7c4", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.149
[INFO] [stderr]    Compiling rustix v0.37.27
[INFO] [stderr]    Compiling tempfile v3.6.0
[INFO] [stderr]    Compiling libm v0.2.8
[INFO] [stderr]    Compiling num-traits v0.2.17
[INFO] [stderr]     Checking either v1.9.0
[INFO] [stderr]     Checking getrandom v0.2.10
[INFO] [stderr]     Checking io-lifetimes v1.0.11
[INFO] [stderr]     Checking wait-timeout v0.2.0
[INFO] [stderr]     Checking rand_core v0.6.4
[INFO] [stderr]     Checking rand_chacha v0.3.1
[INFO] [stderr]     Checking rand_xorshift v0.3.0
[INFO] [stderr]     Checking rand v0.8.5
[INFO] [stderr]     Checking rusty-fork v0.3.0
[INFO] [stderr]     Checking proptest v1.2.0
[INFO] [stderr]     Checking incrementalmerkletree v0.8.2
[INFO] [stderr]     Checking incrementalmerkletree-testing v0.2.0-backcompat.0.8 (/opt/rustwide/workdir)
[INFO] [stdout] error: this type will no longer be must used: Result<Position, Infallible>
[INFO] [stdout]    --> src/complete_tree.rs:414:28
[INFO] [stdout]     |
[INFO] [stdout] 414 |             let position = Position::try_from(i).unwrap();
[INFO] [stdout]     |                            ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `incrementalmerkletree-testing` (lib test) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "78ab536bc09e3d47c4a4fa7917b8e0f84d85c3a9d05f2a98d93364333cb4d7c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "78ab536bc09e3d47c4a4fa7917b8e0f84d85c3a9d05f2a98d93364333cb4d7c4", kill_on_drop: false }`
[INFO] [stdout] 78ab536bc09e3d47c4a4fa7917b8e0f84d85c3a9d05f2a98d93364333cb4d7c4