[INFO] fetching crate panic-rtt-core 0.2.1...
[INFO] checking panic-rtt-core-0.2.1 against master#4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5 for pr-81174
[INFO] extracting crate panic-rtt-core 0.2.1 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate panic-rtt-core 0.2.1 on toolchain 4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate panic-rtt-core 0.2.1
[INFO] finished tweaking crates.io crate panic-rtt-core 0.2.1
[INFO] tweaked toml for crates.io crate panic-rtt-core 0.2.1 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "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] 7dc803052fb84c96dace84add321aed3066e4da0c8780fd2ca98e8bf95dbd3ca
[INFO] running `Command { std: "docker" "start" "-a" "7dc803052fb84c96dace84add321aed3066e4da0c8780fd2ca98e8bf95dbd3ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7dc803052fb84c96dace84add321aed3066e4da0c8780fd2ca98e8bf95dbd3ca", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7dc803052fb84c96dace84add321aed3066e4da0c8780fd2ca98e8bf95dbd3ca", kill_on_drop: false }`
[INFO] [stdout] 7dc803052fb84c96dace84add321aed3066e4da0c8780fd2ca98e8bf95dbd3ca
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7abef684501f272e9939a62fecf8642cab67dc7a0169cc1b4cadec1f2919a1a2
[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" "7abef684501f272e9939a62fecf8642cab67dc7a0169cc1b4cadec1f2919a1a2", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling cortex-m v0.7.1
[INFO] [stderr]     Checking vcell v0.1.3
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.6.6
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]     Checking ufmt-write v0.1.0
[INFO] [stderr]    Compiling generic-array v0.14.4
[INFO] [stderr]     Checking generic-array v0.12.3
[INFO] [stderr]     Checking generic-array v0.13.2
[INFO] [stderr]     Checking volatile-register v0.2.0
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking as-slice v0.1.4
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]     Checking aligned v0.3.4
[INFO] [stderr]     Checking rtt-target v0.2.2
[INFO] [stderr]     Checking panic-rtt-core v0.2.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0152]: found duplicate lang item `panic_impl`
[INFO] [stdout]   --> src/lib.rs:31:1
[INFO] [stdout]    |
[INFO] [stdout] 31 | fn panic(info: &PanicInfo) -> ! {
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: the lang item is first defined in crate `std` (which `test` depends on)
[INFO] [stdout]    = note: first definition in `std` loaded from /opt/rustwide/rustup-home/toolchains/4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-8ca495943bae7405.rlib
[INFO] [stdout]    = note: second definition in the local crate (`panic_rtt_core`)
[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 E0152`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `panic-rtt-core`
[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: build failed
[INFO] running `Command { std: "docker" "inspect" "7abef684501f272e9939a62fecf8642cab67dc7a0169cc1b4cadec1f2919a1a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7abef684501f272e9939a62fecf8642cab67dc7a0169cc1b4cadec1f2919a1a2", kill_on_drop: false }`
[INFO] [stdout] 7abef684501f272e9939a62fecf8642cab67dc7a0169cc1b4cadec1f2919a1a2