[INFO] cloning repository https://github.com/jongrubb/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/jongrubb/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 220d418b638524ddf70aebb9cb64915929b151a1
[INFO] testing jongrubb/rustlings against 1.90.0 for beta-1.91-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjongrubb%2Frustlings" "/workspace/builds/worker-0-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/jongrubb/rustlings
[INFO] finished tweaking git repo https://github.com/jongrubb/rustlings
[INFO] tweaked toml for git repo https://github.com/jongrubb/rustlings written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/jongrubb/rustlings on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/jongrubb/rustlings 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" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b28750dcd33359f6aa9109cfebe23e991a1d37829286073ea1c07d12f078e289
[INFO] running `Command { std: "docker" "start" "-a" "b28750dcd33359f6aa9109cfebe23e991a1d37829286073ea1c07d12f078e289", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b28750dcd33359f6aa9109cfebe23e991a1d37829286073ea1c07d12f078e289", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b28750dcd33359f6aa9109cfebe23e991a1d37829286073ea1c07d12f078e289", kill_on_drop: false }`
[INFO] [stdout] b28750dcd33359f6aa9109cfebe23e991a1d37829286073ea1c07d12f078e289
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ca709aaeeb4062a0bf638fbded6b9adb5ac02db93ec01e825a98c86275d29400
[INFO] running `Command { std: "docker" "start" "-a" "ca709aaeeb4062a0bf638fbded6b9adb5ac02db93ec01e825a98c86275d29400", kill_on_drop: false }`
[INFO] [stderr]    Compiling exercises v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0599]: no method named `as_ref` found for type parameter `T` in the current scope
[INFO] [stdout]  --> exercises/23_conversions/as_ref_mut.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn byte_counter<T>(arg: T) -> usize {
[INFO] [stdout]   |                 - method `as_ref` not found for this type parameter
[INFO] [stdout] 9 |     arg.as_ref().len()
[INFO] [stdout]   |         ^^^^^^ method not found in `T`
[INFO] [stdout]   |
[INFO] [stdout]   = help: items from traits can only be used if the type parameter is bounded by the trait
[INFO] [stdout] help: the following trait defines an item `as_ref`, perhaps you need to restrict type parameter `T` with it:
[INFO] [stdout]   |
[INFO] [stdout] 8 | fn byte_counter<T: AsRef</* T */>>(arg: T) -> usize {
[INFO] [stdout]   |                  ++++++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `as_ref` found for type parameter `T` in the current scope
[INFO] [stdout]   --> exercises/23_conversions/as_ref_mut.rs:15:9
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn char_counter<T>(arg: T) -> usize {
[INFO] [stdout]    |                 - method `as_ref` not found for this type parameter
[INFO] [stdout] 15 |     arg.as_ref().chars().count()
[INFO] [stdout]    |         ^^^^^^ method not found in `T`
[INFO] [stdout]    |
[INFO] [stdout]    = help: items from traits can only be used if the type parameter is bounded by the trait
[INFO] [stdout] help: the following trait defines an item `as_ref`, perhaps you need to restrict type parameter `T` with it:
[INFO] [stdout]    |
[INFO] [stdout] 14 | fn char_counter<T: AsRef</* T */>>(arg: T) -> usize {
[INFO] [stdout]    |                  ++++++++++++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `arg`
[INFO] [stdout]   --> exercises/23_conversions/as_ref_mut.rs:20:14
[INFO] [stdout]    |
[INFO] [stdout] 20 | fn num_sq<T>(arg: &mut T) {
[INFO] [stdout]    |              ^^^ help: if this is intentional, prefix it with an underscore: `_arg`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "as_ref_mut") due to 2 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: cannot divide `f64` by `usize`
[INFO] [stdout]  --> exercises/23_conversions/using_as.rs:8:11
[INFO] [stdout]   |
[INFO] [stdout] 8 |     total / values.len()
[INFO] [stdout]   |           ^ no implementation for `f64 / usize`
[INFO] [stdout]   |
[INFO] [stdout]   = help: the trait `Div<usize>` is not implemented for `f64`
[INFO] [stdout]   = help: the following other types implement trait `Div<Rhs>`:
[INFO] [stdout]             `&f64` implements `Div<f64>`
[INFO] [stdout]             `&f64` implements `Div`
[INFO] [stdout]             `f64` implements `Div<&f64>`
[INFO] [stdout]             `f64` implements `Div`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "using_as") due to 1 previous error
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: a value of type `Vec<i32>` cannot be built from an iterator over elements of type `()`
[INFO] [stdout]   --> exercises/05_vecs/vecs2.rs:29:10
[INFO] [stdout]    |
[INFO] [stdout] 29 |         .collect()
[INFO] [stdout]    |          ^^^^^^^ value of type `Vec<i32>` cannot be built from `std::iter::Iterator<Item=()>`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromIterator<()>` is not implemented for `Vec<i32>`
[INFO] [stdout]            but trait `FromIterator<i32>` is implemented for it
[INFO] [stdout]    = help: for that trait implementation, expected `i32`, found `()`
[INFO] [stdout] note: the method call chain might not have had the expected associated types
[INFO] [stdout]   --> exercises/05_vecs/vecs2.rs:26:10
[INFO] [stdout]    |
[INFO] [stdout] 24 |       input
[INFO] [stdout]    |       ----- this expression has type `&[i32]`
[INFO] [stdout] 25 |           .iter()
[INFO] [stdout]    |            ------ `Iterator::Item` is `&i32` here
[INFO] [stdout] 26 |           .map(|element| {
[INFO] [stdout]    |  __________^
[INFO] [stdout] 27 | |             // ???
[INFO] [stdout] 28 | |         })
[INFO] [stdout]    | |__________^ `Iterator::Item` changed to `()` here
[INFO] [stdout] note: required by a bound in `collect`
[INFO] [stdout]   --> /rustc/1159e78c4747b02ef996e55082b704c09b970588/library/core/src/iter/traits/iterator.rs:2014:5
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `element`
[INFO] [stdout]  --> exercises/05_vecs/vecs2.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     for element in input {
[INFO] [stdout]   |         ^^^^^^^ help: if this is intentional, prefix it with an underscore: `_element`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> exercises/05_vecs/vecs2.rs:2:9
[INFO] [stdout]   |
[INFO] [stdout] 2 |     let mut output = Vec::new();
[INFO] [stdout]   |         ----^^^^^^
[INFO] [stdout]   |         |
[INFO] [stdout]   |         help: remove this `mut`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "vecs2") due to 1 previous error; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "ca709aaeeb4062a0bf638fbded6b9adb5ac02db93ec01e825a98c86275d29400", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca709aaeeb4062a0bf638fbded6b9adb5ac02db93ec01e825a98c86275d29400", kill_on_drop: false }`
[INFO] [stdout] ca709aaeeb4062a0bf638fbded6b9adb5ac02db93ec01e825a98c86275d29400
