[INFO] cloning repository https://github.com/magmast/mill
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/magmast/mill" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmagmast%2Fmill", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmagmast%2Fmill'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9b765184b99603277c13aa41a2fc86882e5e8e08
[INFO] building magmast/mill against try#8b8eff55bd72abbb57167bc42222a7f91d41cb0d for pr-142134-abi-ast-error
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmagmast%2Fmill" "/workspace/builds/worker-4-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/magmast/mill on toolchain 8b8eff55bd72abbb57167bc42222a7f91d41cb0d
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8b8eff55bd72abbb57167bc42222a7f91d41cb0d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-4-tc2/source/.cargo/config
[INFO] started tweaking git repo https://github.com/magmast/mill
[INFO] finished tweaking git repo https://github.com/magmast/mill
[INFO] tweaked toml for git repo https://github.com/magmast/mill written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/magmast/mill 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" "+8b8eff55bd72abbb57167bc42222a7f91d41cb0d" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded embedded-hal v0.2.4
[INFO] [stderr]   Downloaded panic-semihosting v0.5.3
[INFO] [stderr]   Downloaded embedded-dma v0.1.2
[INFO] [stderr]   Downloaded cortex-m-rt-macros v0.1.8
[INFO] [stderr]   Downloaded cortex-m-rt v0.6.12
[INFO] [stderr]   Downloaded as-slice v0.1.3
[INFO] [stderr]   Downloaded aligned v0.3.4
[INFO] [stderr]   Downloaded cortex-m-semihosting v0.3.5
[INFO] [stderr]   Downloaded rtcc v0.2.1
[INFO] [stderr]   Downloaded stm32f4xx-hal v0.9.0
[INFO] [stderr]   Downloaded cortex-m v0.7.3
[INFO] [stderr]   Downloaded stm32f4 v0.13.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+8b8eff55bd72abbb57167bc42222a7f91d41cb0d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c31ee5075eaadfd03b48788722851385ae61d2d59491eb3ab12a7a8cdb9f717e
[INFO] running `Command { std: "docker" "start" "-a" "c31ee5075eaadfd03b48788722851385ae61d2d59491eb3ab12a7a8cdb9f717e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c31ee5075eaadfd03b48788722851385ae61d2d59491eb3ab12a7a8cdb9f717e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c31ee5075eaadfd03b48788722851385ae61d2d59491eb3ab12a7a8cdb9f717e", kill_on_drop: false }`
[INFO] [stdout] c31ee5075eaadfd03b48788722851385ae61d2d59491eb3ab12a7a8cdb9f717e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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=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:eea15d5475069c3ef791f10c2c6b5af2ee421ef2da1e680ecce1cba46243983b" "/opt/rustwide/cargo-home/bin/cargo" "+8b8eff55bd72abbb57167bc42222a7f91d41cb0d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d275ae2d32dcc03929595128e29c68751369f7e966a5f75e4bbf53c498cdc459
[INFO] running `Command { std: "docker" "start" "-a" "d275ae2d32dcc03929595128e29c68751369f7e966a5f75e4bbf53c498cdc459", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling cortex-m v0.7.3
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling vcell v0.1.2
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling syn v1.0.38
[INFO] [stderr]    Compiling cortex-m v0.6.7
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]    Compiling cortex-m-semihosting v0.3.5
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling stm32f4 v0.13.0
[INFO] [stderr]    Compiling embedded-dma v0.1.2
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling embedded-hal v0.2.4
[INFO] [stderr]    Compiling bare-metal v1.0.0
[INFO] [stderr]    Compiling arrayvec v0.5.1
[INFO] [stderr]    Compiling panic-halt v0.2.0
[INFO] [stderr]    Compiling hd44780-driver v0.3.0 (https://github.com/JohnDoneth/hd44780-driver#84a30c5a)
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling cast v0.2.3
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling generic-array v0.13.2
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling as-slice v0.1.3
[INFO] [stderr]    Compiling chrono v0.4.19
[INFO] [stderr]    Compiling aligned v0.3.4
[INFO] [stderr]    Compiling panic-semihosting v0.5.3
[INFO] [stderr]    Compiling rtcc v0.2.1
[INFO] [stderr]    Compiling cortex-m-rt-macros v0.1.8
[INFO] [stderr]    Compiling stm32f4xx-hal v0.9.0
[INFO] [stderr]    Compiling mill v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/lib.rs:167:9
[INFO] [stdout]     |
[INFO] [stdout] 167 |         rtc.set_seconds(0);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 167 |         let _ = rtc.set_seconds(0);
[INFO] [stdout]     |         +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: unwinding panics are not supported without std
[INFO] [stdout]   |
[INFO] [stdout]   = help: using nightly cargo, use -Zbuild-std with panic="abort" to avoid unwinding
[INFO] [stdout]   = note: since the core library is usually precompiled with panic="unwind", rebuilding your crate with panic="abort" may not be enough to fix the problem
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mill` (bin "mill") due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "d275ae2d32dcc03929595128e29c68751369f7e966a5f75e4bbf53c498cdc459", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d275ae2d32dcc03929595128e29c68751369f7e966a5f75e4bbf53c498cdc459", kill_on_drop: false }`
[INFO] [stdout] d275ae2d32dcc03929595128e29c68751369f7e966a5f75e4bbf53c498cdc459