[INFO] fetching crate serde_json_matcher 0.1.5...
[INFO] testing serde_json_matcher-0.1.5 against master#caccb4d0368bd918ef6668af8e13834d07040417 for pr-146098-1
[INFO] extracting crate serde_json_matcher 0.1.5 into /workspace/builds/worker-5-tc1/source
[INFO] started tweaking crates.io crate serde_json_matcher 0.1.5
[INFO] finished tweaking crates.io crate serde_json_matcher 0.1.5
[INFO] tweaked toml for crates.io crate serde_json_matcher 0.1.5 written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate serde_json_matcher 0.1.5 on toolchain caccb4d0368bd918ef6668af8e13834d07040417
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate serde_json_matcher 0.1.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_json v1.0.90
[INFO] [stderr]   Downloaded proc-macro2 v1.0.48
[INFO] [stderr]   Downloaded quote v1.0.22
[INFO] [stderr]   Downloaded serde_derive v1.0.151
[INFO] [stderr]   Downloaded syn v1.0.106
[INFO] [stderr]   Downloaded serde v1.0.151
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/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" "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" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 893b050720894fb383a3034008e8002a748fba5256ad1bb8e0befbc9eea9b9c9
[INFO] running `Command { std: "docker" "start" "-a" "893b050720894fb383a3034008e8002a748fba5256ad1bb8e0befbc9eea9b9c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "893b050720894fb383a3034008e8002a748fba5256ad1bb8e0befbc9eea9b9c9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "893b050720894fb383a3034008e8002a748fba5256ad1bb8e0befbc9eea9b9c9", kill_on_drop: false }`
[INFO] [stdout] 893b050720894fb383a3034008e8002a748fba5256ad1bb8e0befbc9eea9b9c9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc1/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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+caccb4d0368bd918ef6668af8e13834d07040417" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7c4f53b5a37256877f7367dfa3c558196ccd5624ea12d05f5f0d9edce86fe2eb
[INFO] running `Command { std: "docker" "start" "-a" "7c4f53b5a37256877f7367dfa3c558196ccd5624ea12d05f5f0d9edce86fe2eb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.48
[INFO] [stderr]    Compiling quote v1.0.22
[INFO] [stderr]    Compiling unicode-ident v1.0.6
[INFO] [stderr]    Compiling syn v1.0.106
[INFO] [stderr]    Compiling serde_derive v1.0.151
[INFO] [stderr]    Compiling serde v1.0.151
[INFO] [stderr]    Compiling serde_json v1.0.90
[INFO] [stderr]    Compiling itoa v1.0.5
[INFO] [stderr]    Compiling ryu v1.0.12
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.48/src/lib.rs:92:30
[INFO] [stdout]    |
[INFO] [stdout] 92 |     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `proc-macro2` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "7c4f53b5a37256877f7367dfa3c558196ccd5624ea12d05f5f0d9edce86fe2eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c4f53b5a37256877f7367dfa3c558196ccd5624ea12d05f5f0d9edce86fe2eb", kill_on_drop: false }`
[INFO] [stdout] 7c4f53b5a37256877f7367dfa3c558196ccd5624ea12d05f5f0d9edce86fe2eb