[INFO] updating cached repository https://github.com/adamreeve/mio-server
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4c8cb526175abc63ca500757e2cd4a5c1dc8e933
[INFO] testing adamreeve/mio-server against 1.45.2 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fadamreeve%2Fmio-server" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/adamreeve/mio-server on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/adamreeve/mio-server
[INFO] finished tweaking git repo https://github.com/adamreeve/mio-server
[INFO] tweaked toml for git repo https://github.com/adamreeve/mio-server written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/adamreeve/mio-server already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-3/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[INFO] the lockfile is outdated, regenerating it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" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] f18a7a60092dcf77fc21d7d7bda5e939473f1918ae41200fb1101e4ef1f068aa
[INFO] running `Command { std: "docker" "start" "-a" "f18a7a60092dcf77fc21d7d7bda5e939473f1918ae41200fb1101e4ef1f068aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f18a7a60092dcf77fc21d7d7bda5e939473f1918ae41200fb1101e4ef1f068aa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f18a7a60092dcf77fc21d7d7bda5e939473f1918ae41200fb1101e4ef1f068aa", kill_on_drop: false }`
[INFO] [stdout] f18a7a60092dcf77fc21d7d7bda5e939473f1918ae41200fb1101e4ef1f068aa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "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] 53c6443086510128dab1972712668296505d48397b38cc7c2a349443c789566a
[INFO] running `Command { std: "docker" "start" "-a" "53c6443086510128dab1972712668296505d48397b38cc7c2a349443c789566a", kill_on_drop: false }`
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]    Compiling winapi v0.2.8
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling utf8-ranges v0.1.3
[INFO] [stderr]    Compiling regex-syntax v0.3.9
[INFO] [stderr]    Compiling bitflags v0.4.0
[INFO] [stderr]    Compiling slab v0.1.3
[INFO] [stderr]    Compiling bytes v0.3.0
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling net2 v0.2.34
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]    Compiling nix v0.5.1
[INFO] [stderr]    Compiling aho-corasick v0.5.3
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]    Compiling ws2_32-sys v0.2.1
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling miow v0.1.5
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling log v0.3.9
[INFO] [stderr]    Compiling regex v0.1.80
[INFO] [stderr]    Compiling mio v0.5.1
[INFO] [stderr]    Compiling env_logger v0.3.5
[INFO] [stderr]    Compiling mio-server v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(result_expect)]
[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 `mio-server`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "53c6443086510128dab1972712668296505d48397b38cc7c2a349443c789566a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "53c6443086510128dab1972712668296505d48397b38cc7c2a349443c789566a", kill_on_drop: false }`
[INFO] [stdout] 53c6443086510128dab1972712668296505d48397b38cc7c2a349443c789566a