[INFO] cloning repository https://github.com/Big-B/guided-rocket-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Big-B/guided-rocket-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBig-B%2Fguided-rocket-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBig-B%2Fguided-rocket-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 66c9b04de7cb29a68bf2645d6540084f14b6b1b3
[INFO] testing Big-B/guided-rocket-rs against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBig-B%2Fguided-rocket-rs" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Big-B/guided-rocket-rs on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-9/source/.cargo/config
[INFO] started tweaking git repo https://github.com/Big-B/guided-rocket-rs
[INFO] finished tweaking git repo https://github.com/Big-B/guided-rocket-rs
[INFO] tweaked toml for git repo https://github.com/Big-B/guided-rocket-rs written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/Big-B/guided-rocket-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 29e03da1c85d35e9629b0be6b03a7cffdfa933b4d95ff44a47acd9f144a72d84
[INFO] running `Command { std: "docker" "start" "-a" "29e03da1c85d35e9629b0be6b03a7cffdfa933b4d95ff44a47acd9f144a72d84", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "29e03da1c85d35e9629b0be6b03a7cffdfa933b4d95ff44a47acd9f144a72d84", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "29e03da1c85d35e9629b0be6b03a7cffdfa933b4d95ff44a47acd9f144a72d84", kill_on_drop: false }`
[INFO] [stdout] 29e03da1c85d35e9629b0be6b03a7cffdfa933b4d95ff44a47acd9f144a72d84
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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=warn" "-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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] df327b914b8d50cf38afdadecf4a0d613f68be893c5d51ff3fadc16421e1a4a2
[INFO] running `Command { std: "docker" "start" "-a" "df327b914b8d50cf38afdadecf4a0d613f68be893c5d51ff3fadc16421e1a4a2", kill_on_drop: false }`
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.10
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling libm v0.2.1
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]    Compiling stable_deref_trait v1.1.1
[INFO] [stderr]    Compiling cortex-m v0.6.2
[INFO] [stderr]    Compiling cortex-m-rt v0.6.12
[INFO] [stderr]    Compiling vcell v0.1.2
[INFO] [stderr]    Compiling nb v0.1.2
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling libc v0.2.69
[INFO] [stderr]    Compiling atsamd21g18a v0.6.0 (https://github.com/atsamd-rs/atsamd#b7619155)
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]    Compiling r0 v0.2.2
[INFO] [stderr]    Compiling libm v0.1.4
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling bitfield v0.13.2
[INFO] [stderr]    Compiling arduino_mkrzero v0.6.0 (https://github.com/atsamd-rs/atsamd#b7619155)
[INFO] [stderr]    Compiling heapless v0.4.4
[INFO] [stderr]    Compiling panic-halt v0.2.0
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling volatile-register v0.2.0
[INFO] [stderr]    Compiling embedded-hal v0.2.3
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling hash32 v0.1.1
[INFO] [stderr]    Compiling embedded-sdmmc v0.3.0 (https://github.com/thejpster/embedded-sdmmc-rs#5d7a5744)
[INFO] [stderr]    Compiling quote v1.0.3
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling generic-array v0.13.2
[INFO] [stderr]    Compiling generic-array v0.11.1
[INFO] [stderr]    Compiling as-slice v0.1.3
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling alga v0.9.3
[INFO] [stderr]    Compiling aligned v0.3.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/heapless-0.4.4/src/lib.rs:92:35
[INFO] [stdout]    |
[INFO] [stdout] 92 | #![cfg_attr(feature = "const-fn", feature(const_fn))]
[INFO] [stdout]    |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/heapless-0.4.4/src/lib.rs:93:35
[INFO] [stdout]    |
[INFO] [stdout] 93 | #![cfg_attr(feature = "const-fn", feature(untagged_unions))]
[INFO] [stdout]    |                                   ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `heapless`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "df327b914b8d50cf38afdadecf4a0d613f68be893c5d51ff3fadc16421e1a4a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "df327b914b8d50cf38afdadecf4a0d613f68be893c5d51ff3fadc16421e1a4a2", kill_on_drop: false }`
[INFO] [stdout] df327b914b8d50cf38afdadecf4a0d613f68be893c5d51ff3fadc16421e1a4a2