[INFO] fetching crate geen 0.0.7...
[INFO] testing geen-0.0.7 against 1.49.0 for beta-1.50-1
[INFO] extracting crate geen 0.0.7 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate geen 0.0.7 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] started tweaking crates.io crate geen 0.0.7
[INFO] finished tweaking crates.io crate geen 0.0.7
[INFO] tweaked toml for crates.io crate geen 0.0.7 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] 6b77f44cafb3f2f7152df83851a9d0296f96a43e4239658d5a7817fa199702c2
[INFO] running `Command { std: "docker" "start" "-a" "6b77f44cafb3f2f7152df83851a9d0296f96a43e4239658d5a7817fa199702c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b77f44cafb3f2f7152df83851a9d0296f96a43e4239658d5a7817fa199702c2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b77f44cafb3f2f7152df83851a9d0296f96a43e4239658d5a7817fa199702c2", kill_on_drop: false }`
[INFO] [stdout] 6b77f44cafb3f2f7152df83851a9d0296f96a43e4239658d5a7817fa199702c2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] 62b9ed5eae3b50850f2dac0aaa799c9a3a4aa87402633ee052d62d2b89612bbe
[INFO] running `Command { std: "docker" "start" "-a" "62b9ed5eae3b50850f2dac0aaa799c9a3a4aa87402633ee052d62d2b89612bbe", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling glob v0.2.11
[INFO] [stderr]    Compiling cc v1.0.66
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling quick-error v1.2.3
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling termcolor v1.1.2
[INFO] [stderr]    Compiling tiny-keccak v2.0.2
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling getrandom v0.2.1
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling bindgen v0.37.4
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling peeking_take_while v0.1.2
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling adler v0.2.3
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling gimli v0.23.0
[INFO] [stderr]    Compiling object v0.22.0
[INFO] [stderr]    Compiling packed_simd v0.3.3
[INFO] [stderr]    Compiling rustc-demangle v0.1.18
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling smallvec v1.6.0
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling subtle v2.4.0
[INFO] [stderr]    Compiling anyhow v1.0.37
[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/subtle-2.4.0/src/lib.rs:12:34
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![cfg_attr(feature = "nightly", feature(external_doc))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `subtle`
[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" "62b9ed5eae3b50850f2dac0aaa799c9a3a4aa87402633ee052d62d2b89612bbe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "62b9ed5eae3b50850f2dac0aaa799c9a3a4aa87402633ee052d62d2b89612bbe", kill_on_drop: false }`
[INFO] [stdout] 62b9ed5eae3b50850f2dac0aaa799c9a3a4aa87402633ee052d62d2b89612bbe