[INFO] fetching crate feather_m0 0.6.1...
[INFO] testing feather_m0-0.6.1 against beta-2020-06-03 for beta-1.45-1
[INFO] extracting crate feather_m0 0.6.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate feather_m0 0.6.1 on toolchain beta-2020-06-03
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate feather_m0 0.6.1
[INFO] removed 0 missing examples
[INFO] finished tweaking crates.io crate feather_m0 0.6.1
[INFO] tweaked toml for crates.io crate feather_m0 0.6.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate feather_m0 0.6.1 already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=warn" "-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" "+beta-2020-06-03" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 522db11f729d2b99d02254d868a976b89e8babc3d095deb97d59b90f125b794d
[INFO] running `"docker" "start" "-a" "522db11f729d2b99d02254d868a976b89e8babc3d095deb97d59b90f125b794d"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling proc-macro2 v1.0.8
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling typenum v1.11.2
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling cortex-m v0.6.2
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling vcell v0.1.2
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]    Compiling atsamd21g18a v0.6.0
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stderr]    Compiling nb v0.1.2
[INFO] [stderr]    Compiling void v1.0.2
[INFO] [stderr]    Compiling feather_m0 v0.6.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: could not compile `vcell`.
[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] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error[E0463]: can't find crate for `core`
[INFO] [stderr]   |
[INFO] [stderr]   = note: the `thumbv6m-none-eabi` target may not be installed
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0463`.
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "522db11f729d2b99d02254d868a976b89e8babc3d095deb97d59b90f125b794d"`
[INFO] running `"docker" "rm" "-f" "522db11f729d2b99d02254d868a976b89e8babc3d095deb97d59b90f125b794d"`
[INFO] [stdout] 522db11f729d2b99d02254d868a976b89e8babc3d095deb97d59b90f125b794d