[INFO] updating cached repository https://github.com/matthiaskrgr/gitgc
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c8ef1b7ba01cec29039157ef7f26b026ee247c36
[INFO] testing matthiaskrgr/gitgc against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatthiaskrgr%2Fgitgc" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/matthiaskrgr/gitgc on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/matthiaskrgr/gitgc
[INFO] finished tweaking git repo https://github.com/matthiaskrgr/gitgc
[INFO] tweaked toml for git repo https://github.com/matthiaskrgr/gitgc written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/matthiaskrgr/gitgc already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] warning: the cargo feature `edition` is now stable and is no longer necessary to be listed in the manifest
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 6d72a1a582aa692e5ed723fbafcb5bbabd731528dca727ca1fb346181f1aa637
[INFO] running `"docker" "start" "-a" "6d72a1a582aa692e5ed723fbafcb5bbabd731528dca727ca1fb346181f1aa637"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr] warning: the cargo feature `edition` is now stable and is no longer necessary to be listed in the manifest
[INFO] [stderr]    Compiling same-file v1.0.3
[INFO] [stderr]    Compiling log v0.4.5
[INFO] [stderr]    Compiling libz-sys v1.0.20
[INFO] [stderr]    Compiling openssl-sys v0.9.35
[INFO] [stderr]    Compiling cmake v0.1.33
[INFO] [stderr]    Compiling curl-sys v0.4.8
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling walkdir v2.2.5
[INFO] [stderr]    Compiling libssh2-sys v0.2.10
[INFO] [stderr]    Compiling libgit2-sys v0.7.7
[INFO] [stderr]    Compiling url v1.7.1
[INFO] [stderr]    Compiling git2 v0.7.5
[INFO] [stderr]    Compiling gitgc v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(tool_lints)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `gitgc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "6d72a1a582aa692e5ed723fbafcb5bbabd731528dca727ca1fb346181f1aa637"`
[INFO] running `"docker" "rm" "-f" "6d72a1a582aa692e5ed723fbafcb5bbabd731528dca727ca1fb346181f1aa637"`
[INFO] [stdout] 6d72a1a582aa692e5ed723fbafcb5bbabd731528dca727ca1fb346181f1aa637