[INFO] fetching crate alloc-cortex-m 0.4.4...
[INFO] testing alloc-cortex-m-0.4.4 against master#c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38 for pr-146098-7
[INFO] extracting crate alloc-cortex-m 0.4.4 into /workspace/builds/worker-1-tc1/source
[INFO] started tweaking crates.io crate alloc-cortex-m 0.4.4
[INFO] finished tweaking crates.io crate alloc-cortex-m 0.4.4
[INFO] tweaked toml for crates.io crate alloc-cortex-m 0.4.4 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate alloc-cortex-m 0.4.4 on toolchain c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate alloc-cortex-m 0.4.4 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" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded linked_list_allocator v0.10.4
[INFO] [stderr]   Downloaded cortex-m-rt-macros v0.6.15
[INFO] [stderr]   Downloaded cortex-m-rt v0.6.15
[INFO] [stderr]   Downloaded r0 v0.2.2
[INFO] [stderr]   Downloaded cortex-m v0.7.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d1c614ed0a1c5d3d644e714721d866dd84d0a8f14b6fd63eeb53c9e463a3b845
[INFO] running `Command { std: "docker" "start" "-a" "d1c614ed0a1c5d3d644e714721d866dd84d0a8f14b6fd63eeb53c9e463a3b845", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d1c614ed0a1c5d3d644e714721d866dd84d0a8f14b6fd63eeb53c9e463a3b845", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d1c614ed0a1c5d3d644e714721d866dd84d0a8f14b6fd63eeb53c9e463a3b845", kill_on_drop: false }`
[INFO] [stdout] d1c614ed0a1c5d3d644e714721d866dd84d0a8f14b6fd63eeb53c9e463a3b845
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a5fc17d2f5a2b4d2ea910b387d11053677f47adb21fc97945840111c32a55a26
[INFO] running `Command { std: "docker" "start" "-a" "a5fc17d2f5a2b4d2ea910b387d11053677f47adb21fc97945840111c32a55a26", kill_on_drop: false }`
[INFO] [stderr]    Compiling nb v1.0.0
[INFO] [stderr]    Compiling cortex-m v0.7.6
[INFO] [stderr]    Compiling vcell v0.1.3
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling linked_list_allocator v0.10.4
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling volatile-register v0.2.1
[INFO] [stderr]    Compiling nb v0.1.3
[INFO] [stderr]    Compiling embedded-hal v0.2.7
[INFO] [stderr]    Compiling alloc-cortex-m v0.4.4 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.89s
[INFO] running `Command { std: "docker" "inspect" "a5fc17d2f5a2b4d2ea910b387d11053677f47adb21fc97945840111c32a55a26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a5fc17d2f5a2b4d2ea910b387d11053677f47adb21fc97945840111c32a55a26", kill_on_drop: false }`
[INFO] [stdout] a5fc17d2f5a2b4d2ea910b387d11053677f47adb21fc97945840111c32a55a26
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c90bcb9571b7aab0d8beaa2ce8a998ffaf079d38" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4b99944da2c82e396a0dc0c3207ba5d9de6a792529c54ea719de58f7308a2184
[INFO] running `Command { std: "docker" "start" "-a" "4b99944da2c82e396a0dc0c3207ba5d9de6a792529c54ea719de58f7308a2184", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.49
[INFO] [stderr]    Compiling syn v1.0.107
[INFO] [stderr]    Compiling cortex-m-rt v0.6.15
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stdout] error[E0635]: unknown feature `proc_macro_span_shrink`
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/proc-macro2-1.0.49/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" "4b99944da2c82e396a0dc0c3207ba5d9de6a792529c54ea719de58f7308a2184", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4b99944da2c82e396a0dc0c3207ba5d9de6a792529c54ea719de58f7308a2184", kill_on_drop: false }`
[INFO] [stdout] 4b99944da2c82e396a0dc0c3207ba5d9de6a792529c54ea719de58f7308a2184