[INFO] updating cached repository https://github.com/EmmaRamirez/rust-and-webassembly-talk
[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] 748cc3a6a1af9143097345bce25b9fecfdc50064
[INFO] checking EmmaRamirez/rust-and-webassembly-talk against master#ba72b15666b2491415aec703a02c2364fe5e2790 for pr-71140
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEmmaRamirez%2Frust-and-webassembly-talk" "/workspace/builds/worker-11/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/EmmaRamirez/rust-and-webassembly-talk on toolchain ba72b15666b2491415aec703a02c2364fe5e2790
[INFO] running `"/workspace/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/EmmaRamirez/rust-and-webassembly-talk
[INFO] finished tweaking git repo https://github.com/EmmaRamirez/rust-and-webassembly-talk
[INFO] tweaked toml for git repo https://github.com/EmmaRamirez/rust-and-webassembly-talk written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/EmmaRamirez/rust-and-webassembly-talk already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "+ba72b15666b2491415aec703a02c2364fe5e2790" "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] cbc8b8b150b9b6fa401e3314745d825434e09a1312141ec1da6613643f483bd9
[INFO] running `"docker" "start" "-a" "cbc8b8b150b9b6fa401e3314745d825434e09a1312141ec1da6613643f483bd9"`
[INFO] [stderr]    Compiling proc-macro2 v0.4.12
[INFO] [stderr]    Compiling serde v1.0.71
[INFO] [stderr]    Compiling ryu v0.2.3
[INFO] [stderr]    Compiling version_check v0.1.4
[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]    Compiling log v0.4.3
[INFO] [stderr]    Compiling lazy_static v1.1.0
[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] 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" "cbc8b8b150b9b6fa401e3314745d825434e09a1312141ec1da6613643f483bd9"`
[INFO] running `"docker" "rm" "-f" "cbc8b8b150b9b6fa401e3314745d825434e09a1312141ec1da6613643f483bd9"`
[INFO] [stdout] cbc8b8b150b9b6fa401e3314745d825434e09a1312141ec1da6613643f483bd9