[INFO] fetching crate mamba 0.3.6...
[INFO] testing mamba-0.3.6 against try#b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b for pr-145330-1
[INFO] extracting crate mamba 0.3.6 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate mamba 0.3.6
[INFO] finished tweaking crates.io crate mamba 0.3.6
[INFO] tweaked toml for crates.io crate mamba 0.3.6 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate mamba 0.3.6 on toolchain b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate mamba 0.3.6 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" "+b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 640742eb349695043c8cdf00566ab9d8b576fb5232256718720a66cf87d8ddde
[INFO] running `Command { std: "docker" "start" "-a" "640742eb349695043c8cdf00566ab9d8b576fb5232256718720a66cf87d8ddde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "640742eb349695043c8cdf00566ab9d8b576fb5232256718720a66cf87d8ddde", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "640742eb349695043c8cdf00566ab9d8b576fb5232256718720a66cf87d8ddde", kill_on_drop: false }`
[INFO] [stdout] 640742eb349695043c8cdf00566ab9d8b576fb5232256718720a66cf87d8ddde
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/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" "+b6ae10aa7319b7ebb6c7b3331dd71a9d6c9c5b4b" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7dbc22881b6ea76c64f5bb0bb4a1d3cba538bac8e479ac0abef16c4c5fdc2311
[INFO] running `Command { std: "docker" "start" "-a" "7dbc22881b6ea76c64f5bb0bb4a1d3cba538bac8e479ac0abef16c4c5fdc2311", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.1.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.47
[INFO] [stderr]    Compiling unicode-ident v1.0.5
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]    Compiling syn v1.0.105
[INFO] [stderr]    Compiling libc v0.2.138
[INFO] [stderr]    Compiling serde_derive v1.0.151
[INFO] [stderr]    Compiling serde v1.0.151
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling num-traits v0.2.15
[INFO] [stderr]    Compiling num-integer v0.1.45
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling serde_json v1.0.89
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling ryu v1.0.11
[INFO] [stderr]    Compiling escargot v0.3.1
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.47/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] [stderr]    Compiling itoa v1.0.4
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling predicates-core v1.0.5
[INFO] [stderr]    Compiling unicode-width v0.1.10
[INFO] [stderr]    Compiling bytecount v0.3.2
[INFO] [stderr]    Compiling ansi_term v0.12.1
[INFO] [stderr]    Compiling termtree v0.4.0
[INFO] [stderr]    Compiling difference v2.0.0
[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" "7dbc22881b6ea76c64f5bb0bb4a1d3cba538bac8e479ac0abef16c4c5fdc2311", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7dbc22881b6ea76c64f5bb0bb4a1d3cba538bac8e479ac0abef16c4c5fdc2311", kill_on_drop: false }`
[INFO] [stdout] 7dbc22881b6ea76c64f5bb0bb4a1d3cba538bac8e479ac0abef16c4c5fdc2311