[INFO] updating cached repository https://github.com/mattdeboard/prepend_line
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e4dc1c7a8266c455ef3c617f4a8b37bd0b4b676c
[INFO] checking mattdeboard/prepend_line against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmattdeboard%2Fprepend_line" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mattdeboard/prepend_line on toolchain e4dba30b9b475d8750370c4dfb49b6541990904d
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "read-manifest" "--manifest-path" "Cargo.toml"`
[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-4/source/Cargo.toml
[INFO] crate git repo https://github.com/mattdeboard/prepend_line already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=forbid" "-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" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 0dc2f6e72b33ddcaffea6af980aed57058b086115aa198fc3783c9c8d67d2598
[INFO] running `"docker" "start" "-a" "0dc2f6e72b33ddcaffea6af980aed57058b086115aa198fc3783c9c8d67d2598"`
[INFO] [stderr]    Compiling proc-macro2 v0.4.12
[INFO] [stderr]    Compiling version_check v0.1.4
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling ryu v0.2.3
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.16
[INFO] [stderr]     Checking ucd-util v0.1.1
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]    Compiling regex v1.0.2
[INFO] [stderr]     Checking utf8-ranges v1.0.0
[INFO] [stderr]    Compiling serde v1.0.71
[INFO] [stderr]    Compiling log v0.4.3
[INFO] [stderr]     Checking unreachable v1.0.0
[INFO] [stderr]     Checking regex-syntax v0.6.2
[INFO] [stderr]     Checking rand v0.4.2
[INFO] [stderr]     Checking memchr v2.0.1
[INFO] [stderr] error[E0658]: use of unstable library feature 'proc_macro_def_site'
[INFO] [stderr]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.4.12/src/unstable.rs:346:27
[INFO] [stderr]     |
[INFO] [stderr] 346 |             Span::Nightly(proc_macro::Span::def_site())
[INFO] [stderr]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: see issue #54724 <https://github.com/rust-lang/rust/issues/54724> for more information
[INFO] [stderr]     = help: add `#![feature(proc_macro_def_site)]` to the crate attributes to enable
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0658`.
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr] error: could not compile `proc-macro2`.
[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 `"docker" "inspect" "0dc2f6e72b33ddcaffea6af980aed57058b086115aa198fc3783c9c8d67d2598"`
[INFO] running `"docker" "rm" "-f" "0dc2f6e72b33ddcaffea6af980aed57058b086115aa198fc3783c9c8d67d2598"`
[INFO] [stdout] 0dc2f6e72b33ddcaffea6af980aed57058b086115aa198fc3783c9c8d67d2598