[INFO] crate json-trait-rs 0.11.0 is already in cache
[INFO] testing json-trait-rs-0.11.0 against try#03a1ea71b075ab964b5278bc6e74cd6c52c36ee0 for pr-74409
[INFO] extracting crate json-trait-rs 0.11.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate json-trait-rs 0.11.0 on toolchain 03a1ea71b075ab964b5278bc6e74cd6c52c36ee0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate json-trait-rs 0.11.0
[INFO] finished tweaking crates.io crate json-trait-rs 0.11.0
[INFO] tweaked toml for crates.io crate json-trait-rs 0.11.0 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2a19baccc8def1e8bdc0bc54868c7a11dc375a4ce67297e930580fa197483112
[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" "2a19baccc8def1e8bdc0bc54868c7a11dc375a4ce67297e930580fa197483112", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2a19baccc8def1e8bdc0bc54868c7a11dc375a4ce67297e930580fa197483112", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2a19baccc8def1e8bdc0bc54868c7a11dc375a4ce67297e930580fa197483112", kill_on_drop: false }`
[INFO] [stdout] 2a19baccc8def1e8bdc0bc54868c7a11dc375a4ce67297e930580fa197483112
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+03a1ea71b075ab964b5278bc6e74cd6c52c36ee0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 38074f95887d98849d24b6f34cafb84b6e7843582df149fcdd26fb062fdd9cb2
[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" "38074f95887d98849d24b6f34cafb84b6e7843582df149fcdd26fb062fdd9cb2", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.35
[INFO] [stderr]    Compiling libc v0.2.73
[INFO] [stderr]    Compiling gimli v0.22.0
[INFO] [stderr]    Compiling adler v0.2.3
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling rustc-demangle v0.1.16
[INFO] [stderr]    Compiling unicode-segmentation v1.6.0
[INFO] [stderr]    Compiling object v0.20.0
[INFO] [stderr]    Compiling join-lazy-fmt v0.9.2
[INFO] [stderr]    Compiling miniz_oxide v0.4.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling addr2line v0.13.0
[INFO] [stderr]    Compiling backtrace v0.3.50
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling strum_macros v0.18.0
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling json-trait-rs v0.11.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:43:12
[INFO] [stdout]    |
[INFO] [stdout] 43 | #![feature(specialization)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:37:5
[INFO] [stdout]    |
[INFO] [stdout] 37 |     warnings,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(incomplete_features)]` implied by `#[deny(warnings)]`
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `json-trait-rs`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "38074f95887d98849d24b6f34cafb84b6e7843582df149fcdd26fb062fdd9cb2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "38074f95887d98849d24b6f34cafb84b6e7843582df149fcdd26fb062fdd9cb2", kill_on_drop: false }`
[INFO] [stdout] 38074f95887d98849d24b6f34cafb84b6e7843582df149fcdd26fb062fdd9cb2