[INFO] cloning repository https://github.com/isabelroses/bellsym
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/isabelroses/bellsym" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fisabelroses%2Fbellsym", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fisabelroses%2Fbellsym'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 581a8e3749be225c3418d09c1eb55e46483fc0e8
[INFO] testing isabelroses/bellsym against try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fisabelroses%2Fbellsym" "/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/isabelroses/bellsym
[INFO] finished tweaking git repo https://github.com/isabelroses/bellsym
[INFO] tweaked toml for git repo https://github.com/isabelroses/bellsym written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/isabelroses/bellsym on toolchain 8de4c7234dd9b97c9d76b58671343fdbbc9a433e
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/isabelroses/bellsym 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" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded serde_derive v1.0.158
[INFO] [stderr]   Downloaded proc-macro2 v1.0.53
[INFO] [stderr]   Downloaded symlink v0.1.0
[INFO] [stderr]   Downloaded serde v1.0.158
[INFO] [stderr]   Downloaded syn v2.0.10
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] dc56384df047ab36a4d9a15bda33f6edcbb7231a84fba68e898da336c2f4f17d
[INFO] running `Command { std: "docker" "start" "-a" "dc56384df047ab36a4d9a15bda33f6edcbb7231a84fba68e898da336c2f4f17d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "dc56384df047ab36a4d9a15bda33f6edcbb7231a84fba68e898da336c2f4f17d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc56384df047ab36a4d9a15bda33f6edcbb7231a84fba68e898da336c2f4f17d", kill_on_drop: false }`
[INFO] [stdout] dc56384df047ab36a4d9a15bda33f6edcbb7231a84fba68e898da336c2f4f17d
[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@sha256:90999bfc7ae267e83380e433d8e61a7c072ca6729e92edbae886d3423b3a6f4c" "/opt/rustwide/cargo-home/bin/cargo" "+8de4c7234dd9b97c9d76b58671343fdbbc9a433e" "build" "--frozen" "--message-format=json" "--target" "x86_64-unknown-linux-musl", kill_on_drop: false }`
[INFO] [stdout] c0dba5c9f8c4669aaca74767429f6fea1ebb66b4ba625c88c1bd9dfbd628bb8f
[INFO] running `Command { std: "docker" "start" "-a" "c0dba5c9f8c4669aaca74767429f6fea1ebb66b4ba625c88c1bd9dfbd628bb8f", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.53
[INFO] [stderr]    Compiling unicode-ident v1.0.8
[INFO] [stderr]    Compiling quote v1.0.26
[INFO] [stderr]    Compiling serde_derive v1.0.158
[INFO] [stderr]    Compiling serde v1.0.158
[INFO] [stderr]    Compiling serde_json v1.0.94
[INFO] [stderr]    Compiling itoa v1.0.6
[INFO] [stderr]    Compiling ryu v1.0.13
[INFO] [stderr]    Compiling symlink v0.1.0
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.53/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" "c0dba5c9f8c4669aaca74767429f6fea1ebb66b4ba625c88c1bd9dfbd628bb8f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c0dba5c9f8c4669aaca74767429f6fea1ebb66b4ba625c88c1bd9dfbd628bb8f", kill_on_drop: false }`
[INFO] [stdout] c0dba5c9f8c4669aaca74767429f6fea1ebb66b4ba625c88c1bd9dfbd628bb8f