[INFO] cloning repository https://github.com/mattdeboard/prepend_line
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mattdeboard/prepend_line" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmattdeboard%2Fprepend_line", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmattdeboard%2Fprepend_line'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e4dc1c7a8266c455ef3c617f4a8b37bd0b4b676c
[INFO] checking mattdeboard/prepend_line against master#b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18 for pr-79470
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmattdeboard%2Fprepend_line" "/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/mattdeboard/prepend_line on toolchain b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mattdeboard/prepend_line
[INFO] finished tweaking git repo https://github.com/mattdeboard/prepend_line
[INFO] tweaked toml for git repo https://github.com/mattdeboard/prepend_line written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/mattdeboard/prepend_line already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7069ddf66416deb3fd4f6d310502b4c0d4f1cd78d28646550e30f6d5f418462d
[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" "7069ddf66416deb3fd4f6d310502b4c0d4f1cd78d28646550e30f6d5f418462d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7069ddf66416deb3fd4f6d310502b4c0d4f1cd78d28646550e30f6d5f418462d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7069ddf66416deb3fd4f6d310502b4c0d4f1cd78d28646550e30f6d5f418462d", kill_on_drop: false }`
[INFO] [stdout] 7069ddf66416deb3fd4f6d310502b4c0d4f1cd78d28646550e30f6d5f418462d
[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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b7ebc6b0c1ba3c27ebb17c0b496ece778ef11e18" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a547980cc3ba1e1d75bdce396cb3130690bcbe0c05caa4a98551abc80ff95937
[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" "a547980cc3ba1e1d75bdce396cb3130690bcbe0c05caa4a98551abc80ff95937", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling version_check v0.1.4
[INFO] [stderr]    Compiling proc-macro2 v0.4.12
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling serde v1.0.71
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]    Compiling ryu v0.2.3
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.16
[INFO] [stderr]    Compiling cfg-if v0.1.5
[INFO] [stderr]    Compiling itoa v0.4.2
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking utf8-ranges v1.0.0
[INFO] [stderr]     Checking regex-syntax v0.6.2
[INFO] [stderr]    Compiling log v0.4.3
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stdout] error[E0658]: use of unstable library feature 'proc_macro_def_site'
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.4.12/src/unstable.rs:346:27
[INFO] [stdout]     |
[INFO] [stdout] 346 |             Span::Nightly(proc_macro::Span::def_site())
[INFO] [stdout]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #54724 <https://github.com/rust-lang/rust/issues/54724> for more information
[INFO] [stdout]     = help: add `#![feature(proc_macro_def_site)]` to the crate attributes to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2`
[INFO] [stdout] For more information about this error, try `rustc --explain E0658`.
[INFO] [stdout] 
[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" "a547980cc3ba1e1d75bdce396cb3130690bcbe0c05caa4a98551abc80ff95937", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a547980cc3ba1e1d75bdce396cb3130690bcbe0c05caa4a98551abc80ff95937", kill_on_drop: false }`
[INFO] [stdout] a547980cc3ba1e1d75bdce396cb3130690bcbe0c05caa4a98551abc80ff95937