[INFO] cloning repository https://github.com/hegza/serpent-cli
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/hegza/serpent-cli" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 87ac972d440cdb434a8b0eae63cb5696493a8026
[INFO] testing hegza/serpent-cli against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fhegza%2Fserpent-cli" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/hegza/serpent-cli 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 git repo https://github.com/hegza/serpent-cli
[INFO] finished tweaking git repo https://github.com/hegza/serpent-cli
[INFO] tweaked toml for git repo https://github.com/hegza/serpent-cli written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/hegza/serpent-cli 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/hegza/serpent-rs`
[INFO] [stderr] error: the lock file /workspace/builds/worker-2/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/hegza/serpent-rs`
[INFO] [stderr]     Updating git repository `https://github.com/hegza/rustpython`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded diff v0.1.12
[INFO] [stderr]   Downloaded toml_edit v0.1.5
[INFO] [stderr]   Downloaded syntex_errors v0.59.1
[INFO] [stderr]   Downloaded ascii v0.9.3
[INFO] [stderr]   Downloaded ucd-util v0.1.8
[INFO] [stderr]   Downloaded measureme v9.0.0
[INFO] [stderr]   Downloaded color-backtrace v0.3.0
[INFO] [stderr]   Downloaded derive_deref v1.1.1
[INFO] [stderr]   Downloaded pin-project-lite v0.2.1
[INFO] [stderr]   Downloaded combine v3.8.1
[INFO] [stderr]   Downloaded fs-err v2.5.0
[INFO] [stderr]   Downloaded rustc-rayon-core v0.3.0
[INFO] [stderr]   Downloaded unic-ucd-ident v0.9.0
[INFO] [stderr]   Downloaded unic-emoji-char v0.9.0
[INFO] [stderr]   Downloaded flexi_logger v0.16.3
[INFO] [stderr]   Downloaded strings v0.1.1
[INFO] [stderr]   Downloaded unic-ucd-version v0.9.0
[INFO] [stderr]   Downloaded unicode_names2 v0.4.0
[INFO] [stderr]   Downloaded unic-char-range v0.9.0
[INFO] [stderr]   Downloaded cargo-toml-builder v0.3.0
[INFO] [stderr]   Downloaded bit-set v0.5.2
[INFO] [stderr]   Downloaded string_cache v0.8.1
[INFO] [stderr]   Downloaded lalrpop v0.19.3
[INFO] [stderr]   Downloaded extprim v1.7.1
[INFO] [stderr]   Downloaded rustfmt v0.10.0
[INFO] [stderr]   Downloaded unic-char-property v0.9.0
[INFO] [stderr]   Downloaded unic-common v0.9.0
[INFO] [stderr]   Downloaded rustc-rayon v0.3.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_lexer v694.0.0
[INFO] [stderr]   Downloaded stacker v0.1.12
[INFO] [stderr]   Downloaded rustc-ap-rustc_arena v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_index v694.0.0
[INFO] [stderr]   Downloaded pico-args v0.3.4
[INFO] [stderr]   Downloaded syntex_pos v0.59.1
[INFO] [stderr]   Downloaded ena v0.14.0
[INFO] [stderr]   Downloaded lalrpop-util v0.19.3
[INFO] [stderr]   Downloaded rustc-ap-rustc_serialize v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_ast_pretty v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_ast v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_graphviz v694.0.0
[INFO] [stderr]   Downloaded psm v0.1.12
[INFO] [stderr]   Downloaded rustc-ap-rustc_data_structures v694.0.0
[INFO] [stderr]   Downloaded syntex_syntax v0.59.1
[INFO] [stderr]   Downloaded rustc-ap-rustc_span v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_macros v694.0.0
[INFO] [stderr]   Downloaded rustc-ap-rustc_target v694.0.0
[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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 90f770889bf4867c78193ae78963de5df683d1a078e11be18226bc37b24bf6a6
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "90f770889bf4867c78193ae78963de5df683d1a078e11be18226bc37b24bf6a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "90f770889bf4867c78193ae78963de5df683d1a078e11be18226bc37b24bf6a6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "90f770889bf4867c78193ae78963de5df683d1a078e11be18226bc37b24bf6a6", kill_on_drop: false }`
[INFO] [stdout] 90f770889bf4867c78193ae78963de5df683d1a078e11be18226bc37b24bf6a6
[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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c237d02e8b968bd2f2398ae68e9d6b3c5ae18a024e9b72314a062c6777c25863
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "c237d02e8b968bd2f2398ae68e9d6b3c5ae18a024e9b72314a062c6777c25863", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling syn v1.0.58
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling memchr v2.3.4
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling typenum v1.12.0
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling version_check v0.9.2
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling cc v1.0.66
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling smallvec v1.6.0
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling serde v1.0.118
[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/smallvec-1.6.0/src/lib.rs:76:37
[INFO] [stdout]    |
[INFO] [stdout] 76 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling regex-syntax v0.6.21
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[INFO] [stderr]    Compiling unicode-width v0.1.8
[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 `smallvec`
[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" "c237d02e8b968bd2f2398ae68e9d6b3c5ae18a024e9b72314a062c6777c25863", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c237d02e8b968bd2f2398ae68e9d6b3c5ae18a024e9b72314a062c6777c25863", kill_on_drop: false }`
[INFO] [stdout] c237d02e8b968bd2f2398ae68e9d6b3c5ae18a024e9b72314a062c6777c25863