[INFO] updating cached repository https://github.com/sabahtalateh/tokio_chat_server
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] dd3ac82fc35f7d0197021598b8b47ade28c53ad6
[INFO] checking sabahtalateh/tokio_chat_server against master#bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc for pr-70917
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsabahtalateh%2Ftokio_chat_server" "/workspace/builds/worker-3/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sabahtalateh/tokio_chat_server on toolchain bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/sabahtalateh/tokio_chat_server
[INFO] finished tweaking git repo https://github.com/sabahtalateh/tokio_chat_server
[INFO] tweaked toml for git repo https://github.com/sabahtalateh/tokio_chat_server written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/sabahtalateh/tokio_chat_server already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "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-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "+bf1f2eedda4fa02b7c9347dd849ed73ddd43dedc" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 84f18eb06b80e54702bba4fcdc06abf5a818ef418ef4e07cc74861a2c5be9135
[INFO] running `"docker" "start" "-a" "84f18eb06b80e54702bba4fcdc06abf5a818ef418ef4e07cc74861a2c5be9135"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking tokio_chat_server v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:44:5
[INFO] [stderr]    |
[INFO] [stderr] 44 |     /// Implicit types declarations in this file can be omitted
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 45 |     let my_fut: MyFut = MyFut::new();
[INFO] [stderr]    |     --------------------------------- rustdoc does not generate documentation for statements
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_doc_comments)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:47:5
[INFO] [stderr]    |
[INFO] [stderr] 47 |       /// Function to use in `AndThen` combinator
[INFO] [stderr]    |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 48 | /     let f: fn(i32) -> Result<i32, ()> = |val| {
[INFO] [stderr] 49 | |         println!("done");
[INFO] [stderr] 50 | |         Ok(val - 100)
[INFO] [stderr] 51 | |     };
[INFO] [stderr]    | |______- rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 | /     /// `AndThen` type returned by `.and_then(closure)` combinator
[INFO] [stderr] 54 | |     /// implements `Future` too so it can be used as regular future
[INFO] [stderr] 55 | |     ///
[INFO] [stderr] 56 | |     /// First generic type parameter is `MyFut` - future that will be polled first
[INFO] [stderr] ...  |
[INFO] [stderr] 62 | |     /// Third is a function that will be applied to the `MyFut` result
[INFO] [stderr] 63 | |     /// It's return type should be the same as second type parameter
[INFO] [stderr]    | |____________________________________________________________________^
[INFO] [stderr] 64 |       let my_fut: AndThen<MyFut, Result<i32, ()>, fn(i32) -> Result<i32, ()>> = my_fut.and_then(f);
[INFO] [stderr]    |       --------------------------------------------------------------------------------------------- rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:66:5
[INFO] [stderr]    |
[INFO] [stderr] 66 | /     /// `Map` type parameterized with 2 args
[INFO] [stderr] 67 | |     ///
[INFO] [stderr] 68 | |     /// First one `AndThen<MyFut, Result<i32, ()>, fn(i32) -> Result<i32, ()>>` is a `Future` to map
[INFO] [stderr] 69 | |     ///
[INFO] [stderr] ...  |
[INFO] [stderr] 74 | |     /// for map because semantics of `AndThen` is to run another future once the previous one completes
[INFO] [stderr] 75 | |     /// and the semantics of `Map` is to map the result of the future from one value to another
[INFO] [stderr]    | |_______________________________________________________________________________________________^
[INFO] [stderr] 76 | /     let my_fut : Map<AndThen<MyFut, Result<i32, ()>, fn(i32) -> Result<i32, ()>>, fn(i32)-> i32>= my_fut.map(|x| {
[INFO] [stderr] 77 | |         x + 1000
[INFO] [stderr] 78 | |     });
[INFO] [stderr]    | |_______- rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:80:5
[INFO] [stderr]    |
[INFO] [stderr] 80 | /     /// Futures should be run onto an executor
[INFO] [stderr] 81 | |     ///
[INFO] [stderr] 82 | |     /// Later we will consider tokio executor instead of
[INFO] [stderr] 83 | |     /// one provided by the future trait
[INFO] [stderr]    | |________________________________________^
[INFO] [stderr] 84 |       let mut s = spawn(my_fut);
[INFO] [stderr]    |       -------------------------- rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] warning: unused doc comment
[INFO] [stderr]   --> examples/future.rs:86:5
[INFO] [stderr]    |
[INFO] [stderr] 86 |     /// Wait for the outer future `Map` which will poll `AndThen`  which in turn will poll `MyFut`
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 87 |     let r = s.wait_future();
[INFO] [stderr]    |     ------------------------ rustdoc does not generate documentation for statements
[INFO] [stderr] 
[INFO] [stderr] error[E0601]: `main` function not found in crate `tokio_chat_server`
[INFO] [stderr]  --> src/main.rs:1:2
[INFO] [stderr]   |
[INFO] [stderr] 1 | 
[INFO] [stderr]   |  ^ consider adding a `main` function to `src/main.rs`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0601`.
[INFO] [stderr] error: could not compile `tokio_chat_server`.
[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" "84f18eb06b80e54702bba4fcdc06abf5a818ef418ef4e07cc74861a2c5be9135"`
[INFO] running `"docker" "rm" "-f" "84f18eb06b80e54702bba4fcdc06abf5a818ef418ef4e07cc74861a2c5be9135"`
[INFO] [stdout] 84f18eb06b80e54702bba4fcdc06abf5a818ef418ef4e07cc74861a2c5be9135
