[INFO] cloning repository https://github.com/mazhewitt/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mazhewitt/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmazhewitt%2Frust-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmazhewitt%2Frust-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9833f934bc4d7ba66ee2ace90b8bbbe6aa76d356
[INFO] testing mazhewitt/rust-playground against master#1f7f8ea0721a3b1eb73e6c6d25cccb371434b320 for pr-154065-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmazhewitt%2Frust-playground" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/mazhewitt/rust-playground
[INFO] finished tweaking git repo https://github.com/mazhewitt/rust-playground
[INFO] tweaked toml for git repo https://github.com/mazhewitt/rust-playground written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/mazhewitt/rust-playground on toolchain 1f7f8ea0721a3b1eb73e6c6d25cccb371434b320
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/mazhewitt/rust-playground 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" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded termtree v0.4.1
[INFO] [stderr]   Downloaded predicates-tree v1.0.9
[INFO] [stderr]   Downloaded predicates-core v1.0.6
[INFO] [stderr]   Downloaded fragile v2.0.0
[INFO] [stderr]   Downloaded downcast v0.10.0
[INFO] [stderr]   Downloaded mockall v0.10.2
[INFO] [stderr]   Downloaded fragile v1.2.2
[INFO] [stderr]   Downloaded mockall_derive v0.10.2
[INFO] [stderr]   Downloaded proc-macro2 v1.0.56
[INFO] [stderr]   Downloaded float-cmp v0.8.0
[INFO] [stderr]   Downloaded predicates v1.0.8
[INFO] [stderr]   Downloaded difference v2.0.0
[INFO] [stderr]   Downloaded mockall_double v0.3.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a2dfd17633cfa6e0dd9f3b963cf689488240efec0926cafa9be8c433f68a882
[INFO] running `Command { std: "docker" "start" "-a" "1a2dfd17633cfa6e0dd9f3b963cf689488240efec0926cafa9be8c433f68a882", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a2dfd17633cfa6e0dd9f3b963cf689488240efec0926cafa9be8c433f68a882", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a2dfd17633cfa6e0dd9f3b963cf689488240efec0926cafa9be8c433f68a882", kill_on_drop: false }`
[INFO] [stdout] 1a2dfd17633cfa6e0dd9f3b963cf689488240efec0926cafa9be8c433f68a882
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1f7f8ea0721a3b1eb73e6c6d25cccb371434b320" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8143c8bf88fb89f6f45035cc06994385248ae2ef846de77aa7f84ae26743ffdb
[INFO] running `Command { std: "docker" "start" "-a" "8143c8bf88fb89f6f45035cc06994385248ae2ef846de77aa7f84ae26743ffdb", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.56
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling regex-syntax v0.6.29
[INFO] [stderr]    Compiling predicates-core v1.0.6
[INFO] [stderr]    Compiling difference v2.0.0
[INFO] [stderr]    Compiling termtree v0.4.1
[INFO] [stderr]    Compiling normalize-line-endings v0.3.0
[INFO] [stderr]    Compiling fragile v2.0.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling downcast v0.10.0
[INFO] [stderr]    Compiling predicates-tree v1.0.9
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling fragile v1.2.2
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.56/src/lib.rs:92:30
[INFO] [stdout]    |
[INFO] [stdout] 92 |     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout]    |                              ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] help: there is a feature with a similar name: `proc_macro_span_file`
[INFO] [stdout]    |
[INFO] [stdout] 92 -     feature(proc_macro_span, proc_macro_span_shrink)
[INFO] [stdout] 92 +     feature(proc_macro_span, proc_macro_span_file)
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling aho-corasick v0.7.20
[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] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "8143c8bf88fb89f6f45035cc06994385248ae2ef846de77aa7f84ae26743ffdb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8143c8bf88fb89f6f45035cc06994385248ae2ef846de77aa7f84ae26743ffdb", kill_on_drop: false }`
[INFO] [stdout] 8143c8bf88fb89f6f45035cc06994385248ae2ef846de77aa7f84ae26743ffdb