[INFO] cloning repository https://github.com/picklenerd/microbit_playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/picklenerd/microbit_playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpicklenerd%2Fmicrobit_playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpicklenerd%2Fmicrobit_playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d4b62fa5bf524fcb9bf3d78d93992ac1b9817510
[INFO] checking picklenerd/microbit_playground against try#4a04890980766cc79878135f5ade8c0c4321e943 for pr-65819
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpicklenerd%2Fmicrobit_playground" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/picklenerd/microbit_playground on toolchain 4a04890980766cc79878135f5ade8c0c4321e943
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/picklenerd/microbit_playground
[INFO] finished tweaking git repo https://github.com/picklenerd/microbit_playground
[INFO] tweaked toml for git repo https://github.com/picklenerd/microbit_playground written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/picklenerd/microbit_playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded cortex-m v0.6.3
[INFO] [stderr]   Downloaded fpa v0.1.0
[INFO] [stderr]   Downloaded cortex-m-rt v0.6.12
[INFO] [stderr]   Downloaded as-slice v0.1.3
[INFO] [stderr]   Downloaded nrf51 v0.7.0
[INFO] [stderr]   Downloaded panic-abort v0.3.2
[INFO] [stderr]   Downloaded nrf51-hal v0.7.1
[INFO] [stderr]   Downloaded microbit v0.8.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/opt/rustwide/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] ee8c8f481aaf1b305476c451fa304e8bd2da7ca96c20a84a2d9732e30983f04b
[INFO] running `Command { std: "docker" "start" "-a" "ee8c8f481aaf1b305476c451fa304e8bd2da7ca96c20a84a2d9732e30983f04b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ee8c8f481aaf1b305476c451fa304e8bd2da7ca96c20a84a2d9732e30983f04b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ee8c8f481aaf1b305476c451fa304e8bd2da7ca96c20a84a2d9732e30983f04b", kill_on_drop: false }`
[INFO] [stdout] ee8c8f481aaf1b305476c451fa304e8bd2da7ca96c20a84a2d9732e30983f04b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:c46a2d1a26fb48b37929c74ca49dd9409f2375a0a3bdb8fe07617f3ffccaa889" "/opt/rustwide/cargo-home/bin/cargo" "+4a04890980766cc79878135f5ade8c0c4321e943" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 97b09386fa1cf11275bbd33a8c1d7c130b745495b7e47dcd064aeb5eb79f01a7
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "97b09386fa1cf11275bbd33a8c1d7c130b745495b7e47dcd064aeb5eb79f01a7", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.38
[INFO] [stderr]    Compiling cortex-m v0.6.3
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]     Checking vcell v0.1.2
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]     Checking r0 v0.2.2
[INFO] [stderr]    Compiling fpa v0.1.0
[INFO] [stderr]    Compiling nrf51 v0.7.0
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]    Compiling microbit v0.8.0
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `stable_deref_trait`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stdout] error[E0463]: can't find crate for `core`
[INFO] [stdout]   |
[INFO] [stdout]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0463`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "97b09386fa1cf11275bbd33a8c1d7c130b745495b7e47dcd064aeb5eb79f01a7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "97b09386fa1cf11275bbd33a8c1d7c130b745495b7e47dcd064aeb5eb79f01a7", kill_on_drop: false }`
[INFO] [stdout] 97b09386fa1cf11275bbd33a8c1d7c130b745495b7e47dcd064aeb5eb79f01a7