[INFO] cloning repository https://github.com/Basharkhan7776/rustling
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Basharkhan7776/rustling" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBasharkhan7776%2Frustling", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBasharkhan7776%2Frustling'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3ce52378ef22b65421df793afddfbb33c64d4eb8
[INFO] testing Basharkhan7776/rustling against master#733b47ea4b1b86216f14ef56e49440c33933f230+rustflags=-Copt-level=3 for pr-138759
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBasharkhan7776%2Frustling" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/Basharkhan7776/rustling
[INFO] finished tweaking git repo https://github.com/Basharkhan7776/rustling
[INFO] tweaked toml for git repo https://github.com/Basharkhan7776/rustling written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/Basharkhan7776/rustling on toolchain 733b47ea4b1b86216f14ef56e49440c33933f230
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/Basharkhan7776/rustling 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" "+733b47ea4b1b86216f14ef56e49440c33933f230" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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" "+733b47ea4b1b86216f14ef56e49440c33933f230" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b878fd59b548969c1526649c12845d819dcab1661589bf15c6d4d876b316277d
[INFO] running `Command { std: "docker" "start" "-a" "b878fd59b548969c1526649c12845d819dcab1661589bf15c6d4d876b316277d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b878fd59b548969c1526649c12845d819dcab1661589bf15c6d4d876b316277d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b878fd59b548969c1526649c12845d819dcab1661589bf15c6d4d876b316277d", kill_on_drop: false }`
[INFO] [stdout] b878fd59b548969c1526649c12845d819dcab1661589bf15c6d4d876b316277d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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 -Copt-level=3" "-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+733b47ea4b1b86216f14ef56e49440c33933f230" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 91f1d79cb6a5211ca4e7f747c0d9d6d8d153499f165f14605e506bf1c5b12722
[INFO] running `Command { std: "docker" "start" "-a" "91f1d79cb6a5211ca4e7f747c0d9d6d8d153499f165f14605e506bf1c5b12722", kill_on_drop: false }`
[INFO] [stderr]    Compiling exercises v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0106]: missing lifetime specifier
[INFO] [stdout]  --> exercises/16_lifetimes/lifetimes1.rs:7:33
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn longest(x: &str, y: &str) -> &str {
[INFO] [stdout]   |               ----     ----     ^ expected named lifetime parameter
[INFO] [stdout]   |
[INFO] [stdout]   = help: this function's return type contains a borrowed value, but the signature does not say whether it is borrowed from `x` or `y`
[INFO] [stdout] help: consider introducing a named lifetime parameter
[INFO] [stdout]   |
[INFO] [stdout] 7 | fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
[INFO] [stdout]   |           ++++     ++          ++          ++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: expected `;`, found `(`
[INFO] [stdout]  --> exercises/21_macros/macros4.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     }
[INFO] [stdout]   |      - expected `;`
[INFO] [stdout] 7 |     ($val:expr) => {
[INFO] [stdout]   |     ^ unexpected token
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `super::Command`
[INFO] [stdout]   --> exercises/quizzes/quiz2.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |     use super::Command;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0106`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "macros4") due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: could not compile `exercises` (bin "lifetimes1") due to 1 previous error
[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] [stdout] For more information about this error, try `rustc --explain E0599`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "as_ref_mut") due to 2 previous errors; 1 warning emitted
[INFO] [stdout] error[E0072]: recursive type `List` has infinite size
[INFO] [stdout]   --> exercises/19_smart_pointers/box1.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | enum List {
[INFO] [stdout]    | ^^^^^^^^^
[INFO] [stdout] 15 |     Cons(i32, List),
[INFO] [stdout]    |               ---- recursive without indirection
[INFO] [stdout]    |
[INFO] [stdout] help: insert some indirection (e.g., a `Box`, `Rc`, or `&`) to break the cycle
[INFO] [stdout]    |
[INFO] [stdout] 15 |     Cons(i32, Box<List>),
[INFO] [stdout]    |               ++++    +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0391]: cycle detected when computing drop-check constraints for `List`
[INFO] [stdout]   --> exercises/19_smart_pointers/box1.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | enum List {
[INFO] [stdout]    | ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: ...which immediately requires computing drop-check constraints for `List` again
[INFO] [stdout]    = note: cycle used when computing dropck types for `List`
[INFO] [stdout]    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0391]: cycle detected when computing when `List` needs drop
[INFO] [stdout]   --> exercises/19_smart_pointers/box1.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | enum List {
[INFO] [stdout]    | ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: ...which immediately requires computing when `List` needs drop again
[INFO] [stdout]    = note: cycle used when computing whether `List` needs drop
[INFO] [stdout]    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0072, E0391.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0072`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `exercises` (bin "box1") due to 3 previous errors
[INFO] running `Command { std: "docker" "inspect" "91f1d79cb6a5211ca4e7f747c0d9d6d8d153499f165f14605e506bf1c5b12722", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "91f1d79cb6a5211ca4e7f747c0d9d6d8d153499f165f14605e506bf1c5b12722", kill_on_drop: false }`
[INFO] [stdout] 91f1d79cb6a5211ca4e7f747c0d9d6d8d153499f165f14605e506bf1c5b12722
