[INFO] cloning repository https://github.com/nrc/cargo-src
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/nrc/cargo-src" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnrc%2Fcargo-src", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnrc%2Fcargo-src'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 328f783ac40245c298ee6c1e9654f4d4e8d46e7b
[INFO] testing nrc/cargo-src against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fnrc%2Fcargo-src" "/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/nrc/cargo-src 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/nrc/cargo-src
[INFO] finished tweaking git repo https://github.com/nrc/cargo-src
[INFO] tweaked toml for git repo https://github.com/nrc/cargo-src written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/nrc/cargo-src 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] 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] ec888df431c765f5a876e5632fca381d6e1e60214500c87b2c836bda5c7fbf14
[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" "ec888df431c765f5a876e5632fca381d6e1e60214500c87b2c836bda5c7fbf14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ec888df431c765f5a876e5632fca381d6e1e60214500c87b2c836bda5c7fbf14", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ec888df431c765f5a876e5632fca381d6e1e60214500c87b2c836bda5c7fbf14", kill_on_drop: false }`
[INFO] [stdout] ec888df431c765f5a876e5632fca381d6e1e60214500c87b2c836bda5c7fbf14
[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] ea25d40f284883c45e7893eac6dad2252e4a8818bfc41c2de5c4e81b8a79a42e
[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" "ea25d40f284883c45e7893eac6dad2252e4a8818bfc41c2de5c4e81b8a79a42e", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling nibble_vec v0.0.4
[INFO] [stderr]    Compiling endian-type v0.1.2
[INFO] [stderr]    Compiling pest v1.0.6
[INFO] [stderr]    Compiling unicode_categories v0.1.1
[INFO] [stderr]    Compiling typed-arena v1.7.0
[INFO] [stderr]    Compiling entities v1.0.1
[INFO] [stderr]    Compiling rls-blacklist v0.1.3
[INFO] [stderr]    Compiling tokio-sync v0.1.7
[INFO] [stderr]    Compiling tokio-service v0.1.0
[INFO] [stderr]    Compiling relay v0.1.1
[INFO] [stderr]    Compiling error-chain v0.12.1
[INFO] [stderr]    Compiling tokio-executor v0.1.8
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling rls-data v0.16.0
[INFO] [stderr]    Compiling rls-vfs v0.4.6
[INFO] [stderr]    Compiling cargo-src v0.1.8 (/opt/rustwide/workdir)
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling num_cpus v1.11.1
[INFO] [stderr]    Compiling net2 v0.2.33
[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/rls-vfs-0.4.6/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(type_ascription)]
[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]    Compiling memchr v0.1.11
[INFO] [stderr] error: could not compile `rls-vfs`
[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" "ea25d40f284883c45e7893eac6dad2252e4a8818bfc41c2de5c4e81b8a79a42e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ea25d40f284883c45e7893eac6dad2252e4a8818bfc41c2de5c4e81b8a79a42e", kill_on_drop: false }`
[INFO] [stdout] ea25d40f284883c45e7893eac6dad2252e4a8818bfc41c2de5c4e81b8a79a42e