Dec 19 12:58:59.940 INFO checking mattdeboard/prepend_line against try#e70472fc501b855c9080f3772432c10fe20b8866 for pr-56955
Dec 19 12:58:59.940 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56955/worker-5/try#e70472fc501b855c9080f3772432c10fe20b8866:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-56955/sources/try#e70472fc501b855c9080f3772432c10fe20b8866/gh/mattdeboard/prepend_line:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+e70472fc501b855c9080f3772432c10fe20b8866-alt" "check" "--frozen" "--all" "--all-targets"`
Dec 19 12:59:00.529 INFO [stdout] 5315a6f9b41b849509ab8a6d93079648c5a0cbdfb5d632e523f7ff3dc40030d7
Dec 19 12:59:00.534 INFO running `"docker" "start" "-a" "5315a6f9b41b849509ab8a6d93079648c5a0cbdfb5d632e523f7ff3dc40030d7"`
Dec 19 12:59:02.140 INFO [stderr]    Compiling proc-macro2 v0.4.12
Dec 19 12:59:02.140 INFO [stderr]    Compiling serde_json v1.0.26
Dec 19 12:59:02.140 INFO [stderr]     Checking uuid v0.1.18
Dec 19 12:59:03.261 INFO [stderr]     Checking mktemp v0.3.1
Dec 19 12:59:03.272 INFO [stderr] error[E0658]: use of unstable library feature 'proc_macro_def_site' (see issue #54724)
Dec 19 12:59:03.272 INFO [stderr]    --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.4.12/src/unstable.rs:346:27
Dec 19 12:59:03.272 INFO [stderr]     |
Dec 19 12:59:03.272 INFO [stderr] 346 |             Span::Nightly(proc_macro::Span::def_site())
Dec 19 12:59:03.272 INFO [stderr]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 19 12:59:03.272 INFO [stderr]     |
Dec 19 12:59:03.272 INFO [stderr]     = help: add #![feature(proc_macro_def_site)] to the crate attributes to enable
Dec 19 12:59:03.272 INFO [stderr] 
Dec 19 12:59:03.292 INFO [stderr] error: aborting due to previous error
Dec 19 12:59:03.317 INFO [stderr] 
Dec 19 12:59:03.317 INFO [stderr] For more information about this error, try `rustc --explain E0658`.
Dec 19 12:59:03.338 INFO [stderr] error: Could not compile `proc-macro2`.
Dec 19 12:59:03.338 INFO [stderr] warning: build failed, waiting for other jobs to finish...
Dec 19 12:59:07.346 INFO [stderr] error: build failed
Dec 19 12:59:08.565 INFO running `"docker" "inspect" "5315a6f9b41b849509ab8a6d93079648c5a0cbdfb5d632e523f7ff3dc40030d7"`
Dec 19 12:59:08.902 INFO running `"docker" "rm" "-f" "5315a6f9b41b849509ab8a6d93079648c5a0cbdfb5d632e523f7ff3dc40030d7"`
Dec 19 12:59:09.224 INFO [stdout] 5315a6f9b41b849509ab8a6d93079648c5a0cbdfb5d632e523f7ff3dc40030d7