[INFO] cloning repository https://github.com/upenn-cis198-2018f/lecture8
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/upenn-cis198-2018f/lecture8" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fupenn-cis198-2018f%2Flecture8", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fupenn-cis198-2018f%2Flecture8'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 539f8f443639491be71409f0248499065a58b53d
[INFO] checking upenn-cis198-2018f/lecture8 against master#8f359beca4e58bc3ae795a666301a8f47023044c for pr-121557
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fupenn-cis198-2018f%2Flecture8" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/upenn-cis198-2018f/lecture8 on toolchain 8f359beca4e58bc3ae795a666301a8f47023044c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8f359beca4e58bc3ae795a666301a8f47023044c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/upenn-cis198-2018f/lecture8
[INFO] finished tweaking git repo https://github.com/upenn-cis198-2018f/lecture8
[INFO] tweaked toml for git repo https://github.com/upenn-cis198-2018f/lecture8 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/upenn-cis198-2018f/lecture8 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" "+8f359beca4e58bc3ae795a666301a8f47023044c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking upenn-cis198-2018f/lecture8 against try#80d5fe37e16a0befb4128414cb6a11d544788c0a for pr-121557
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fupenn-cis198-2018f%2Flecture8" "/workspace/builds/worker-2-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/upenn-cis198-2018f/lecture8 on toolchain 80d5fe37e16a0befb4128414cb6a11d544788c0a
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+80d5fe37e16a0befb4128414cb6a11d544788c0a" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/upenn-cis198-2018f/lecture8
[INFO] finished tweaking git repo https://github.com/upenn-cis198-2018f/lecture8
[INFO] tweaked toml for git repo https://github.com/upenn-cis198-2018f/lecture8 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/upenn-cis198-2018f/lecture8 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" "+80d5fe37e16a0befb4128414cb6a11d544788c0a" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+80d5fe37e16a0befb4128414cb6a11d544788c0a" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f52d3fd7e9df24fef95014c4669f35b4b95afbc5f15f340973927165c33a9e4e
[INFO] running `Command { std: "docker" "start" "-a" "f52d3fd7e9df24fef95014c4669f35b4b95afbc5f15f340973927165c33a9e4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f52d3fd7e9df24fef95014c4669f35b4b95afbc5f15f340973927165c33a9e4e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f52d3fd7e9df24fef95014c4669f35b4b95afbc5f15f340973927165c33a9e4e", kill_on_drop: false }`
[INFO] [stdout] f52d3fd7e9df24fef95014c4669f35b4b95afbc5f15f340973927165c33a9e4e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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" "-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+80d5fe37e16a0befb4128414cb6a11d544788c0a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 23a574f4ee1a8978b2cdf4e7ff813d287d3e466aa29d701444677226e65034cb
[INFO] running `Command { std: "docker" "start" "-a" "23a574f4ee1a8978b2cdf4e7ff813d287d3e466aa29d701444677226e65034cb", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.93
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]     Checking nix v0.20.0
[INFO] [stderr]     Checking lecture8 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
[INFO] [stdout]    --> src/unsafe_code.rs:159:9
[INFO] [stdout]     |
[INFO] [stdout] 158 |         let mutable = shared as *const i32 as *mut i32;
[INFO] [stdout]     |                       -------------------------------- casting happend here
[INFO] [stdout] 159 |         *mutable = 20;
[INFO] [stdout]     |         ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
[INFO] [stdout]     = note: `#[deny(invalid_reference_casting)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: assigning to `&T` is undefined behavior, consider using an `UnsafeCell`
[INFO] [stdout]    --> src/unsafe_code.rs:159:9
[INFO] [stdout]     |
[INFO] [stdout] 158 |         let mutable = shared as *const i32 as *mut i32;
[INFO] [stdout]     |                       -------------------------------- casting happend here
[INFO] [stdout] 159 |         *mutable = 20;
[INFO] [stdout]     |         ^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: for more information, visit <https://doc.rust-lang.org/book/ch15-05-interior-mutability.html>
[INFO] [stdout]     = note: `#[deny(invalid_reference_casting)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lecture8` (bin "lecture8") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lecture8` (bin "lecture8" test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "23a574f4ee1a8978b2cdf4e7ff813d287d3e466aa29d701444677226e65034cb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "23a574f4ee1a8978b2cdf4e7ff813d287d3e466aa29d701444677226e65034cb", kill_on_drop: false }`
[INFO] [stdout] 23a574f4ee1a8978b2cdf4e7ff813d287d3e466aa29d701444677226e65034cb