[INFO] updating cached repository https://github.com/techlunacy/twitter-markov-trender
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 5e8d6e2cb43bca5386972ca5e95272f4e0bcffdc
[INFO] checking techlunacy/twitter-markov-trender against try#0ab79c4b48ad19260fa46623f452c1b403a360e8 for pr-74315
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftechlunacy%2Ftwitter-markov-trender" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/techlunacy/twitter-markov-trender on toolchain 0ab79c4b48ad19260fa46623f452c1b403a360e8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0ab79c4b48ad19260fa46623f452c1b403a360e8" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/techlunacy/twitter-markov-trender
[INFO] finished tweaking git repo https://github.com/techlunacy/twitter-markov-trender
[INFO] tweaked toml for git repo https://github.com/techlunacy/twitter-markov-trender written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/techlunacy/twitter-markov-trender already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0ab79c4b48ad19260fa46623f452c1b403a360e8" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+0ab79c4b48ad19260fa46623f452c1b403a360e8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 83438ff63a7b12c15e4064038845cb5e1d9d9aadf35dc38e8f6501bc66d78817
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "83438ff63a7b12c15e4064038845cb5e1d9d9aadf35dc38e8f6501bc66d78817", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "83438ff63a7b12c15e4064038845cb5e1d9d9aadf35dc38e8f6501bc66d78817", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "83438ff63a7b12c15e4064038845cb5e1d9d9aadf35dc38e8f6501bc66d78817", kill_on_drop: false }`
[INFO] [stdout] 83438ff63a7b12c15e4064038845cb5e1d9d9aadf35dc38e8f6501bc66d78817
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+0ab79c4b48ad19260fa46623f452c1b403a360e8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] fc1e1844e4604ed7f32f74334a39014f7e29b7f1906881faa58ee7539d97148e
[INFO] running `Command { std: "docker" "start" "-a" "fc1e1844e4604ed7f32f74334a39014f7e29b7f1906881faa58ee7539d97148e", kill_on_drop: false }`
[INFO] [stderr]     Checking twitter_markov_trender v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]  --> src/main.rs:6:14
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let keys = chain.iter().flat_map(|s| s.split_whitespace().next()).collect();
[INFO] [stdout]   |         ---- consider giving `keys` a type
[INFO] [stdout] ...
[INFO] [stdout] 6 |     for i in keys.iter() {
[INFO] [stdout]   |              ^^^^ cannot infer type
[INFO] [stdout]   |
[INFO] [stdout]   = note: type must be known at this point
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `twitter_markov_trender`.
[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] [stdout] error[E0282]: type annotations needed
[INFO] [stdout]  --> src/main.rs:6:14
[INFO] [stdout]   |
[INFO] [stdout] 3 |     let keys = chain.iter().flat_map(|s| s.split_whitespace().next()).collect();
[INFO] [stdout]   |         ---- consider giving `keys` a type
[INFO] [stdout] ...
[INFO] [stdout] 6 |     for i in keys.iter() {
[INFO] [stdout]   |              ^^^^ cannot infer type
[INFO] [stdout]   |
[INFO] [stdout]   = note: type must be known at this point
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0282`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "fc1e1844e4604ed7f32f74334a39014f7e29b7f1906881faa58ee7539d97148e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fc1e1844e4604ed7f32f74334a39014f7e29b7f1906881faa58ee7539d97148e", kill_on_drop: false }`
[INFO] [stdout] fc1e1844e4604ed7f32f74334a39014f7e29b7f1906881faa58ee7539d97148e