[INFO] cloning repository https://github.com/jrheard/rustbook
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jrheard/rustbook" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjrheard%2Frustbook"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjrheard%2Frustbook'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 751299e1df274231b14a0687fbe79103b6090fcc
[INFO] checking jrheard/rustbook against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjrheard%2Frustbook" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jrheard/rustbook on toolchain e4dba30b9b475d8750370c4dfb49b6541990904d
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/jrheard/rustbook
[INFO] finished tweaking git repo https://github.com/jrheard/rustbook
[INFO] tweaked toml for git repo https://github.com/jrheard/rustbook written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/jrheard/rustbook already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] ee6285938a8ac387615f73c0813b8f1d17b69f5cf5f0b34ff7ffd58efec89ca3
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "ee6285938a8ac387615f73c0813b8f1d17b69f5cf5f0b34ff7ffd58efec89ca3"`
[INFO] [stderr]     Checking chapter_8_exercises v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused import: `assert_approx_eq::assert_approx_eq`
[INFO] [stderr]  --> src/main.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use assert_approx_eq::assert_approx_eq;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `chapter_8_exercises`
[INFO] [stderr]    --> src/main.rs:3:1
[INFO] [stderr]     |
[INFO] [stderr] 3   | / use std::collections::HashMap;
[INFO] [stderr] 4   | |
[INFO] [stderr] 5   | | use assert_approx_eq::assert_approx_eq;
[INFO] [stderr] 6   | |
[INFO] [stderr] ...   |
[INFO] [stderr] 176 | |
[INFO] [stderr] 177 | | }
[INFO] [stderr]     | |_^ consider adding a `main` function to `src/main.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error; 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `chapter_8_exercises`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "ee6285938a8ac387615f73c0813b8f1d17b69f5cf5f0b34ff7ffd58efec89ca3"`
[INFO] running `"docker" "rm" "-f" "ee6285938a8ac387615f73c0813b8f1d17b69f5cf5f0b34ff7ffd58efec89ca3"`
[INFO] [stdout] ee6285938a8ac387615f73c0813b8f1d17b69f5cf5f0b34ff7ffd58efec89ca3