[INFO] fetching crate alloc-cortex-m 0.4.4...
[INFO] testing alloc-cortex-m-0.4.4 against try#c2e32f1c9652b13ed99608599c1e855462f421f3 for pr-146098-7
[INFO] extracting crate alloc-cortex-m 0.4.4 into /workspace/builds/worker-1-tc2/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-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate alloc-cortex-m 0.4.4 on toolchain c2e32f1c9652b13ed99608599c1e855462f421f3
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "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" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 22b139967963884c8613fe9ee1b8cacee90d54d981309e5e52423743a193dff0
[INFO] running `Command { std: "docker" "start" "-a" "22b139967963884c8613fe9ee1b8cacee90d54d981309e5e52423743a193dff0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "22b139967963884c8613fe9ee1b8cacee90d54d981309e5e52423743a193dff0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "22b139967963884c8613fe9ee1b8cacee90d54d981309e5e52423743a193dff0", kill_on_drop: false }`
[INFO] [stdout] 22b139967963884c8613fe9ee1b8cacee90d54d981309e5e52423743a193dff0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 997f60d0132c3e244cbf559e71e6abc2742a55a30c6a6dfea4dee0ea5d2b370e
[INFO] running `Command { std: "docker" "start" "-a" "997f60d0132c3e244cbf559e71e6abc2742a55a30c6a6dfea4dee0ea5d2b370e", 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 0.88s
[INFO] running `Command { std: "docker" "inspect" "997f60d0132c3e244cbf559e71e6abc2742a55a30c6a6dfea4dee0ea5d2b370e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "997f60d0132c3e244cbf559e71e6abc2742a55a30c6a6dfea4dee0ea5d2b370e", kill_on_drop: false }`
[INFO] [stdout] 997f60d0132c3e244cbf559e71e6abc2742a55a30c6a6dfea4dee0ea5d2b370e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+c2e32f1c9652b13ed99608599c1e855462f421f3" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ada8de46d6696eb67a625237459eb891bda5fb10cab2b865938418bbe570cf60
[INFO] running `Command { std: "docker" "start" "-a" "ada8de46d6696eb67a625237459eb891bda5fb10cab2b865938418bbe570cf60", 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" "ada8de46d6696eb67a625237459eb891bda5fb10cab2b865938418bbe570cf60", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ada8de46d6696eb67a625237459eb891bda5fb10cab2b865938418bbe570cf60", kill_on_drop: false }`
[INFO] [stdout] ada8de46d6696eb67a625237459eb891bda5fb10cab2b865938418bbe570cf60