[INFO] cloning repository https://github.com/nbardiuk/mazes
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nbardiuk/mazes" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnbardiuk%2Fmazes", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnbardiuk%2Fmazes'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 888a96302611db487c41fcf8f050032ddf535b44
[INFO] building nbardiuk/mazes against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnbardiuk%2Fmazes" "/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/nbardiuk/mazes on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/nbardiuk/mazes
[INFO] finished tweaking git repo https://github.com/nbardiuk/mazes
[INFO] tweaked toml for git repo https://github.com/nbardiuk/mazes written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/nbardiuk/mazes 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" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded svg v0.6.0
[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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4bbb8ea347ecb00b8b1c44fcb1e640f7f7d04fecb297984b92a4b0d335729d26
[INFO] running `Command { std: "docker" "start" "-a" "4bbb8ea347ecb00b8b1c44fcb1e640f7f7d04fecb297984b92a4b0d335729d26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4bbb8ea347ecb00b8b1c44fcb1e640f7f7d04fecb297984b92a4b0d335729d26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4bbb8ea347ecb00b8b1c44fcb1e640f7f7d04fecb297984b92a4b0d335729d26", kill_on_drop: false }`
[INFO] [stdout] 4bbb8ea347ecb00b8b1c44fcb1e640f7f7d04fecb297984b92a4b0d335729d26
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6f96a9ff2be453e069d939f5917d8e6045acc75a98a60ffc4a0324571e7f17fe
[INFO] running `Command { std: "docker" "start" "-a" "6f96a9ff2be453e069d939f5917d8e6045acc75a98a60ffc4a0324571e7f17fe", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling getrandom v0.1.12
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling svg v0.6.0
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling mazes v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Rng`
[INFO] [stdout]  --> src/binary_tree.rs:4:24
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rand::{thread_rng, Rng};
[INFO] [stdout]   |                        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/maze.rs:175:13
[INFO] [stdout]     |
[INFO] [stdout] 175 |         for x in 0..self.width {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct `BinaryTree` is never constructed
[INFO] [stdout]  --> src/binary_tree.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub struct BinaryTree;
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function `on` is never used
[INFO] [stdout]  --> src/binary_tree.rs:8:12
[INFO] [stdout]   |
[INFO] [stdout] 7 | impl BinaryTree {
[INFO] [stdout]   | --------------- associated function in this implementation
[INFO] [stdout] 8 |     pub fn on(mut maze: Maze) -> Maze {
[INFO] [stdout]   |            ^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: method `links` is never used
[INFO] [stdout]   --> src/maze.rs:92:12
[INFO] [stdout]    |
[INFO] [stdout] 32 | impl Maze {
[INFO] [stdout]    | --------- method in this implementation
[INFO] [stdout] ...
[INFO] [stdout] 92 |     pub fn links(&self, cell: &Cell) -> Vec<Cell> {
[INFO] [stdout]    |            ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.45s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: svg v0.6.0
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "6f96a9ff2be453e069d939f5917d8e6045acc75a98a60ffc4a0324571e7f17fe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6f96a9ff2be453e069d939f5917d8e6045acc75a98a60ffc4a0324571e7f17fe", kill_on_drop: false }`
[INFO] [stdout] 6f96a9ff2be453e069d939f5917d8e6045acc75a98a60ffc4a0324571e7f17fe
[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 -Dtail-expr-drop-order" "-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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2989cb49f48bdcc6094101126df2607d96cc07e94de47d2cd654aa1db2b3c83c
[INFO] running `Command { std: "docker" "start" "-a" "2989cb49f48bdcc6094101126df2607d96cc07e94de47d2cd654aa1db2b3c83c", kill_on_drop: false }`
[INFO] [stderr]    Compiling mazes v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Rng`
[INFO] [stdout]  --> src/binary_tree.rs:4:24
[INFO] [stdout]   |
[INFO] [stdout] 4 | use rand::{thread_rng, Rng};
[INFO] [stdout]   |                        ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]    --> src/maze.rs:175:13
[INFO] [stdout]     |
[INFO] [stdout] 175 |         for x in 0..self.width {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.76s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: svg v0.6.0
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "2989cb49f48bdcc6094101126df2607d96cc07e94de47d2cd654aa1db2b3c83c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2989cb49f48bdcc6094101126df2607d96cc07e94de47d2cd654aa1db2b3c83c", kill_on_drop: false }`
[INFO] [stdout] 2989cb49f48bdcc6094101126df2607d96cc07e94de47d2cd654aa1db2b3c83c