[INFO] fetching crate postrs 0.1.0...
[INFO] testing postrs-0.1.0 against try#8de4c7234dd9b97c9d76b58671343fdbbc9a433e+target=x86_64-unknown-linux-musl for musl_upgrade_1_2_5_with_libc_patch_0
[INFO] extracting crate postrs 0.1.0 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate postrs 0.1.0
[INFO] finished tweaking crates.io crate postrs 0.1.0
[INFO] tweaked toml for crates.io crate postrs 0.1.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate postrs 0.1.0 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 postrs 0.1.0 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]  Downloading crates ...
[INFO] [stderr]   Downloaded validator_derive v0.15.0
[INFO] [stderr]   Downloaded validator_types v0.15.0
[INFO] [stderr]   Downloaded validator v0.15.0
[INFO] [stderr]   Downloaded proc-macro2 v1.0.48
[INFO] [stderr]   Downloaded quote v1.0.22
[INFO] [stderr]   Downloaded syn v1.0.106
[INFO] [stderr]   Downloaded serde_json v1.0.90
[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] 957f7fe66e36ba7956f6bcecaa0c1187fe99526d9bccc15c66414aed0fee47b8
[INFO] running `Command { std: "docker" "start" "-a" "957f7fe66e36ba7956f6bcecaa0c1187fe99526d9bccc15c66414aed0fee47b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "957f7fe66e36ba7956f6bcecaa0c1187fe99526d9bccc15c66414aed0fee47b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "957f7fe66e36ba7956f6bcecaa0c1187fe99526d9bccc15c66414aed0fee47b8", kill_on_drop: false }`
[INFO] [stdout] 957f7fe66e36ba7956f6bcecaa0c1187fe99526d9bccc15c66414aed0fee47b8
[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] e8b78950deb72228cfcefca3484751ade5487b68c9060a0458cd8cd8dcdf1cfe
[INFO] running `Command { std: "docker" "start" "-a" "e8b78950deb72228cfcefca3484751ade5487b68c9060a0458cd8cd8dcdf1cfe", 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 memchr v2.5.0
[INFO] [stderr]    Compiling syn v1.0.106
[INFO] [stderr]    Compiling version_check v0.9.4
[INFO] [stderr]    Compiling tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling serde_derive v1.0.151
[INFO] [stderr]    Compiling serde v1.0.151
[INFO] [stderr]    Compiling unicode-bidi v0.3.8
[INFO] [stderr]    Compiling serde_json v1.0.90
[INFO] [stderr]    Compiling percent-encoding v2.2.0
[INFO] [stderr]    Compiling regex-syntax v0.6.28
[INFO] [stderr]    Compiling if_chain v1.0.2
[INFO] [stderr]    Compiling itoa v1.0.5
[INFO] [stderr]    Compiling tinyvec v1.6.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling ryu v1.0.12
[INFO] [stderr]    Compiling matches v0.1.9
[INFO] [stderr]    Compiling form_urlencoded v1.1.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[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]    Compiling aho-corasick v0.7.20
[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" "e8b78950deb72228cfcefca3484751ade5487b68c9060a0458cd8cd8dcdf1cfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e8b78950deb72228cfcefca3484751ade5487b68c9060a0458cd8cd8dcdf1cfe", kill_on_drop: false }`
[INFO] [stdout] e8b78950deb72228cfcefca3484751ade5487b68c9060a0458cd8cd8dcdf1cfe