[INFO] updating cached repository https://github.com/kdnk/rust_introduction
[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] 4a644f9533c899940a70df93d978e23509f90120
[INFO] checking kdnk/rust_introduction against try#a243773eaf3fedcd203f10ae4579e4f106bf7ccd for pr-68325
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkdnk%2Frust_introduction" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/kdnk/rust_introduction on toolchain a243773eaf3fedcd203f10ae4579e4f106bf7ccd
[INFO] running `"/workspace/cargo-home/bin/cargo" "+a243773eaf3fedcd203f10ae4579e4f106bf7ccd" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/kdnk/rust_introduction
[INFO] finished tweaking git repo https://github.com/kdnk/rust_introduction
[INFO] tweaked toml for git repo https://github.com/kdnk/rust_introduction written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/kdnk/rust_introduction already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+a243773eaf3fedcd203f10ae4579e4f106bf7ccd" "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-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" "/opt/rustwide/cargo-home/bin/cargo" "+a243773eaf3fedcd203f10ae4579e4f106bf7ccd" "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] 4a4f23cb524423e787cb2a86d3ba6acc8ebc12559a8a78bf4d9fa8d8419abe6d
[INFO] running `"docker" "start" "-a" "4a4f23cb524423e787cb2a86d3ba6acc8ebc12559a8a78bf4d9fa8d8419abe6d"`
[INFO] [stderr]     Checking rust_introduction v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error: couldn't read src/07_ownership/01_value_ownership.rs: No such file or directory (os error 2)
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: couldn't read src/07_ownership/04_borrow.rs: No such file or directory (os error 2)
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: couldn't read src/07_ownership/use_toy_vec.rs: No such file or directory (os error 2)
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: couldn't read src/07_ownership/03_copy.rs: No such file or directory (os error 2)
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: couldn't read src/07_ownership/01_value_ownership.rs: No such file or directory (os error 2)
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]  --> src/08_trait/03_dispatch.rs:8:34
[INFO] [stderr]   |
[INFO] [stderr] 8 |     <i32 as ToString>::to_string(t)
[INFO] [stderr]   |                                  ^
[INFO] [stderr]   |                                  |
[INFO] [stderr]   |                                  expected `&i32`, found `i32`
[INFO] [stderr]   |                                  help: consider borrowing here: `&t`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0308`.
[INFO] [stderr] error: could not compile `rust_introduction`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] warning: value passed to `n` is never read
[INFO] [stderr]  --> src/04_primitive/scalar.rs:5:11
[INFO] [stderr]   |
[INFO] [stderr] 5 | fn f1(mut n: u32) {
[INFO] [stderr]   |           ^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_assignments)]` on by default
[INFO] [stderr]   = help: maybe it is overwritten before being read?
[INFO] [stderr] 
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "4a4f23cb524423e787cb2a86d3ba6acc8ebc12559a8a78bf4d9fa8d8419abe6d"`
[INFO] running `"docker" "rm" "-f" "4a4f23cb524423e787cb2a86d3ba6acc8ebc12559a8a78bf4d9fa8d8419abe6d"`
[INFO] [stdout] 4a4f23cb524423e787cb2a86d3ba6acc8ebc12559a8a78bf4d9fa8d8419abe6d