[INFO] fetching crate nucleo-l031k6-bsp 0.3.0...
[INFO] building nucleo-l031k6-bsp-0.3.0 against master#c7f6aa2869acdbf014d094c6e427e554e160b6db for pr-146237-2
[INFO] extracting crate nucleo-l031k6-bsp 0.3.0 into /workspace/builds/worker-5-tc1/source
[INFO] removed /workspace/builds/worker-5-tc1/source/.cargo/config
[INFO] started tweaking crates.io crate nucleo-l031k6-bsp 0.3.0
[INFO] finished tweaking crates.io crate nucleo-l031k6-bsp 0.3.0
[INFO] tweaked toml for crates.io crate nucleo-l031k6-bsp 0.3.0 written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate nucleo-l031k6-bsp 0.3.0 on toolchain c7f6aa2869acdbf014d094c6e427e554e160b6db
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate nucleo-l031k6-bsp 0.3.0 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" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded unicode-ident v1.0.5
[INFO] [stderr]   Downloaded volatile-register v0.2.1
[INFO] [stderr]   Downloaded stm32l0x1-hal v0.11.0
[INFO] [stderr]   Downloaded proc-macro2 v1.0.47
[INFO] [stderr]   Downloaded cortex-m-rt v0.7.2
[INFO] [stderr]   Downloaded panic-halt v0.2.0
[INFO] [stderr]   Downloaded flash-embedded-hal v0.1.2
[INFO] [stderr]   Downloaded bare-metal v1.0.0
[INFO] [stderr]   Downloaded cortex-m-rt-macros v0.7.0
[INFO] [stderr]   Downloaded nb v1.0.0
[INFO] [stderr]   Downloaded cortex-m v0.7.6
[INFO] [stderr]   Downloaded syn v1.0.103
[INFO] [stderr]   Downloaded stm32l0 v0.15.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e0654a987d65af1ff9672621d199bef78149f8e9e66211e0b806107a6fe9cc98
[INFO] running `Command { std: "docker" "start" "-a" "e0654a987d65af1ff9672621d199bef78149f8e9e66211e0b806107a6fe9cc98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e0654a987d65af1ff9672621d199bef78149f8e9e66211e0b806107a6fe9cc98", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e0654a987d65af1ff9672621d199bef78149f8e9e66211e0b806107a6fe9cc98", kill_on_drop: false }`
[INFO] [stdout] e0654a987d65af1ff9672621d199bef78149f8e9e66211e0b806107a6fe9cc98
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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=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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+c7f6aa2869acdbf014d094c6e427e554e160b6db" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3f43a1cb6424b99fcb33db885025387c678db2cd133c00005bec18f241425b8d
[INFO] running `Command { std: "docker" "start" "-a" "3f43a1cb6424b99fcb33db885025387c678db2cd133c00005bec18f241425b8d", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.47
[INFO] [stderr]    Compiling unicode-ident v1.0.5
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]    Compiling syn v1.0.103
[INFO] [stderr]    Compiling cortex-m v0.7.6
[INFO] [stderr]    Compiling cortex-m-rt v0.7.2
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling stm32l0 v0.15.1
[INFO] [stderr]    Compiling bare-metal v1.0.0
[INFO] [stderr]    Compiling cast v0.3.0
[INFO] [stderr]    Compiling flash-embedded-hal v0.1.2
[INFO] [stderr]    Compiling panic-halt v0.2.0
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling volatile-register v0.2.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling embedded-hal v0.2.7
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.47/src/lib.rs:92:30
[INFO] [stdout]    |
[INFO] [stdout] 92 |     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "3f43a1cb6424b99fcb33db885025387c678db2cd133c00005bec18f241425b8d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f43a1cb6424b99fcb33db885025387c678db2cd133c00005bec18f241425b8d", kill_on_drop: false }`
[INFO] [stdout] 3f43a1cb6424b99fcb33db885025387c678db2cd133c00005bec18f241425b8d