Dec 05 15:08:25.017 INFO testing mattdeboard/prepend_line against try#6eb0fd3ac58f9b16bddb9924a17c3b6c156aa468 for pr-56514
Dec 05 15:08:25.017 INFO running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-56514/worker-4/try#6eb0fd3ac58f9b16bddb9924a17c3b6c156aa468:/target:rw,Z" "-v" "/mnt/big/crater/work/local/test-source/worker-4/pr-56514/try#6eb0fd3ac58f9b16bddb9924a17c3b6c156aa468:/source:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/source" "-e" "USER_ID=1000" "-e" "CMD=cargo +6eb0fd3ac58f9b16bddb9924a17c3b6c156aa468-alt build --frozen" "-e" "CARGO_TARGET_DIR=/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/cargo-home" "-e" "RUSTUP_HOME=/rustup-home" "-m" "1536M" "--network" "none" "crater"`
Dec 05 15:08:25.256 INFO [stdout] 46525c2c69c741383dfb5eb4f9bd2fd42f34f2d743b8f49f7d0ecca7cff9deb3
Dec 05 15:08:25.266 INFO running `"docker" "start" "-a" "46525c2c69c741383dfb5eb4f9bd2fd42f34f2d743b8f49f7d0ecca7cff9deb3"`
Dec 05 15:08:25.889 INFO [stderr] usermod: no changes
Dec 05 15:08:25.985 INFO [stderr]    Compiling proc-macro2 v0.4.12
Dec 05 15:08:25.985 INFO [stderr]    Compiling rand v0.3.22
Dec 05 15:08:26.248 INFO [stderr]    Compiling uuid v0.1.18
Dec 05 15:08:26.593 INFO [stderr] error[E0658]: use of unstable library feature 'proc_macro_def_site' (see issue #54724)
Dec 05 15:08:26.593 INFO [stderr]    --> /cargo-home/registry/src/github.com-1ecc6299db9ec823/proc-macro2-0.4.12/src/unstable.rs:346:27
Dec 05 15:08:26.593 INFO [stderr]     |
Dec 05 15:08:26.593 INFO [stderr] 346 |             Span::Nightly(proc_macro::Span::def_site())
Dec 05 15:08:26.593 INFO [stderr]     |                           ^^^^^^^^^^^^^^^^^^^^^^^^^^
Dec 05 15:08:26.593 INFO [stderr]     |
Dec 05 15:08:26.593 INFO [stderr]     = help: add #![feature(proc_macro_def_site)] to the crate attributes to enable
Dec 05 15:08:26.593 INFO [stderr] 
Dec 05 15:08:26.612 INFO [stderr] error: aborting due to previous error
Dec 05 15:08:26.612 INFO [stderr] 
Dec 05 15:08:26.612 INFO [stderr] For more information about this error, try `rustc --explain E0658`.
Dec 05 15:08:26.620 INFO [stderr] error: Could not compile `proc-macro2`.
Dec 05 15:08:26.620 INFO [stderr] warning: build failed, waiting for other jobs to finish...
Dec 05 15:08:27.232 INFO [stderr] error: build failed
Dec 05 15:08:27.234 INFO [stderr] su: No module specific data is present
Dec 05 15:08:27.834 INFO running `"docker" "inspect" "46525c2c69c741383dfb5eb4f9bd2fd42f34f2d743b8f49f7d0ecca7cff9deb3"`
Dec 05 15:08:28.052 INFO running `"docker" "rm" "-f" "46525c2c69c741383dfb5eb4f9bd2fd42f34f2d743b8f49f7d0ecca7cff9deb3"`
Dec 05 15:08:28.355 INFO [stdout] 46525c2c69c741383dfb5eb4f9bd2fd42f34f2d743b8f49f7d0ecca7cff9deb3