[INFO] updating cached repository https://github.com/PatrickStephansen/websynth
[INFO] running `Command { std: "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", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0185c4509d9019a61b83336d8a4e35b25fb23921
[INFO] testing PatrickStephansen/websynth against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FPatrickStephansen%2Fwebsynth" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/PatrickStephansen/websynth on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/PatrickStephansen/websynth
[INFO] finished tweaking git repo https://github.com/PatrickStephansen/websynth
[INFO] tweaked toml for git repo https://github.com/PatrickStephansen/websynth written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/PatrickStephansen/websynth already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 56d1ab272e406b1d2527d32d1f5c303dd9ac92732487d555f7005029edf618b7
[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" "56d1ab272e406b1d2527d32d1f5c303dd9ac92732487d555f7005029edf618b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "56d1ab272e406b1d2527d32d1f5c303dd9ac92732487d555f7005029edf618b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "56d1ab272e406b1d2527d32d1f5c303dd9ac92732487d555f7005029edf618b7", kill_on_drop: false }`
[INFO] [stdout] 56d1ab272e406b1d2527d32d1f5c303dd9ac92732487d555f7005029edf618b7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0fd1135a12c1138089040424ea90ca5886001b57d95ed444baea665a053e5dd4
[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" "0fd1135a12c1138089040424ea90ca5886001b57d95ed444baea665a053e5dd4", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling serde v1.0.70
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.15
[INFO] [stderr]    Compiling cfg-if v0.1.4
[INFO] [stderr]    Compiling dtoa v0.4.3
[INFO] [stderr]    Compiling itoa v0.4.2
[INFO] [stderr]    Compiling rand_core v0.2.0
[INFO] [stderr]    Compiling libc v0.2.42
[INFO] [stderr]    Compiling log v0.4.3
[INFO] [stderr]    Compiling proc-macro2 v0.4.9
[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-macro2-0.4.9/src/unstable.rs:347:27
[INFO] [stdout]     |
[INFO] [stdout] 347 |             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] [stdout] For more information about this error, try `rustc --explain E0658`.
[INFO] [stdout] 
[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 `Command { std: "docker" "inspect" "0fd1135a12c1138089040424ea90ca5886001b57d95ed444baea665a053e5dd4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0fd1135a12c1138089040424ea90ca5886001b57d95ed444baea665a053e5dd4", kill_on_drop: false }`
[INFO] [stdout] 0fd1135a12c1138089040424ea90ca5886001b57d95ed444baea665a053e5dd4