[INFO] fetching crate exers 0.2.0...
[INFO] testing exers-0.2.0 against try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] extracting crate exers 0.2.0 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate exers 0.2.0
[INFO] finished tweaking crates.io crate exers 0.2.0
[INFO] tweaked toml for crates.io crate exers 0.2.0 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate exers 0.2.0 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 crates.io crate exers 0.2.0 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]  Downloading crates ...
[INFO] [stderr]   Downloaded lexical-sort v0.3.1
[INFO] [stderr]   Downloaded wasmer-wasix-types v0.5.0
[INFO] [stderr]   Downloaded target-lexicon v0.12.7
[INFO] [stderr]   Downloaded uuid v1.3.3
[INFO] [stderr]   Downloaded inkwell_internals v0.7.0
[INFO] [stderr]   Downloaded rkyv_derive v0.7.42
[INFO] [stderr]   Downloaded any_ascii v0.1.7
[INFO] [stderr]   Downloaded wai-bindgen-gen-wasmer v0.2.3
[INFO] [stderr]   Downloaded cooked-waker v5.0.0
[INFO] [stderr]   Downloaded llvm-sys v140.1.0
[INFO] [stderr]   Downloaded pin-project v1.1.0
[INFO] [stderr]   Downloaded heapless v0.7.16
[INFO] [stderr]   Downloaded wasmparser v0.95.0
[INFO] [stderr]   Downloaded virtual-fs v0.3.0
[INFO] [stderr]   Downloaded wasmer-compiler-cranelift v4.0.0-alpha.1
[INFO] [stderr]   Downloaded darling_core v0.20.1
[INFO] [stderr]   Downloaded darling v0.20.1
[INFO] [stderr]   Downloaded pin-project-internal v1.1.0
[INFO] [stderr]   Downloaded hyper-rustls v0.24.0
[INFO] [stderr]   Downloaded tokio-rustls v0.24.0
[INFO] [stderr]   Downloaded wai-bindgen-rust v0.2.3
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[INFO] [stderr]   Downloaded wasmer-compiler-llvm v4.0.0-alpha.1
[INFO] [stderr]   Downloaded openssl-sys v0.9.87
[INFO] [stderr]   Downloaded rustls-webpki v0.100.1
[INFO] [stderr]   Downloaded wast v60.0.0
[INFO] [stderr]   Downloaded inkwell v0.1.1
[INFO] [stderr]   Downloaded wasmer v4.0.0-alpha.1
[INFO] [stderr]   Downloaded winnow v0.4.6
[INFO] [stderr]   Downloaded wasmer-middlewares v4.0.0-alpha.1
[INFO] [stderr]   Downloaded rustls v0.21.1
[INFO] [stderr]   Downloaded openssl v0.10.52
[INFO] [stderr]   Downloaded toml_edit v0.19.10
[INFO] [stderr]   Downloaded wasmer-wasix v0.5.0
[INFO] [stderr]   Downloaded wat v1.0.66
[INFO] [stderr]   Downloaded enumset v1.1.2
[INFO] [stderr]   Downloaded bytecheck v0.6.11
[INFO] [stderr]   Downloaded webc v5.0.1
[INFO] [stderr]   Downloaded critical-section v1.1.1
[INFO] [stderr]   Downloaded term_size v0.3.2
[INFO] [stderr]   Downloaded virtual-net v0.2.0
[INFO] [stderr]   Downloaded wai-bindgen-wasmer v0.5.0
[INFO] [stderr]   Downloaded toml_datetime v0.6.2
[INFO] [stderr]   Downloaded wai-bindgen-gen-core v0.2.3
[INFO] [stderr]   Downloaded wai-bindgen-gen-rust v0.2.3
[INFO] [stderr]   Downloaded wasm-bindgen-downcast v0.1.1
[INFO] [stderr]   Downloaded tracing-attributes v0.1.24
[INFO] [stderr]   Downloaded wasmer-compiler v4.0.0-alpha.1
[INFO] [stderr]   Downloaded corosensei v0.1.3
[INFO] [stderr]   Downloaded wasmer-vm v4.0.0-alpha.1
[INFO] [stderr]   Downloaded wasm-encoder v0.29.0
[INFO] [stderr]   Downloaded darling_macro v0.20.1
[INFO] [stderr]   Downloaded enumset_derive v0.8.1
[INFO] [stderr]   Downloaded bytecheck_derive v0.6.11
[INFO] [stderr]   Downloaded rkyv v0.7.42
[INFO] [stderr]   Downloaded wasm-bindgen-downcast-macros v0.1.1
[INFO] [stderr]   Downloaded region v3.0.0
[INFO] [stderr]   Downloaded wasmer-derive v4.0.0-alpha.1
[INFO] [stderr]   Downloaded atomic-polyfill v0.1.11
[INFO] [stderr]   Downloaded wai-bindgen-wasmer-impl v0.2.3
[INFO] [stderr]   Downloaded wai-bindgen-gen-rust-wasm v0.2.3
[INFO] [stderr]   Downloaded wai-bindgen-rust-impl v0.2.3
[INFO] [stderr]   Downloaded wasmer-types v4.0.0-alpha.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 1bcef3048fa6803d4518d632ae92cee3e268e80773a78343a2724aee4c5d3c49
[INFO] running `Command { std: "docker" "start" "-a" "1bcef3048fa6803d4518d632ae92cee3e268e80773a78343a2724aee4c5d3c49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1bcef3048fa6803d4518d632ae92cee3e268e80773a78343a2724aee4c5d3c49", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1bcef3048fa6803d4518d632ae92cee3e268e80773a78343a2724aee4c5d3c49", kill_on_drop: false }`
[INFO] [stdout] 1bcef3048fa6803d4518d632ae92cee3e268e80773a78343a2724aee4c5d3c49
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] a632c87aa587a73076371c62d58359e4d6d8256332e2117ea1cba2fbe2ab270d
[INFO] running `Command { std: "docker" "start" "-a" "a632c87aa587a73076371c62d58359e4d6d8256332e2117ea1cba2fbe2ab270d", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.59
[INFO] [stderr]    Compiling quote v1.0.28
[INFO] [stderr]    Compiling unicode-ident v1.0.9
[INFO] [stderr]    Compiling libc v0.2.144
[INFO] [stderr]    Compiling serde v1.0.163
[INFO] [stderr]    Compiling syn v1.0.109
[INFO] [stderr]    Compiling ahash v0.7.6
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stderr]    Compiling anyhow v1.0.71
[INFO] [stderr]    Compiling pulldown-cmark v0.8.0
[INFO] [stderr]    Compiling unicode-normalization v0.1.22
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling tracing-core v0.1.31
[INFO] [stderr]    Compiling memoffset v0.8.0
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.59/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 fnv v1.0.7
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling smallvec v1.10.0
[INFO] [stderr]    Compiling thiserror v1.0.40
[INFO] [stderr]    Compiling percent-encoding v2.2.0
[INFO] [stderr]    Compiling form_urlencoded v1.1.0
[INFO] [stderr]    Compiling memchr v2.5.0
[INFO] [stderr]    Compiling lock_api v0.4.9
[INFO] [stderr]    Compiling crossbeam-utils v0.8.15
[INFO] [stderr]    Compiling bytecheck v0.6.11
[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" "a632c87aa587a73076371c62d58359e4d6d8256332e2117ea1cba2fbe2ab270d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a632c87aa587a73076371c62d58359e4d6d8256332e2117ea1cba2fbe2ab270d", kill_on_drop: false }`
[INFO] [stdout] a632c87aa587a73076371c62d58359e4d6d8256332e2117ea1cba2fbe2ab270d