[INFO] updating cached repository https://github.com/tynr426/regex_learn
[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] f59ec04f199a67c8bdaebe162b45a52c8b8e4cb5
[INFO] checking tynr426/regex_learn against try#e4dba30b9b475d8750370c4dfb49b6541990904d for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fregex_learn" "/workspace/builds/worker-6/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tynr426/regex_learn on toolchain e4dba30b9b475d8750370c4dfb49b6541990904d
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/tynr426/regex_learn
[INFO] finished tweaking git repo https://github.com/tynr426/regex_learn
[INFO] tweaked toml for git repo https://github.com/tynr426/regex_learn written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/tynr426/regex_learn already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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=forbid" "-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" "+e4dba30b9b475d8750370c4dfb49b6541990904d" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] edb7c6ceb0d6dfe2efd86f81df8f042453e6b31810dd4f790757ffac313b1743
[INFO] running `"docker" "start" "-a" "edb7c6ceb0d6dfe2efd86f81df8f042453e6b31810dd4f790757ffac313b1743"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking memchr v2.2.1
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking regex_learn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:55:9
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let mut str2 = "{xy:7,xx:\"kk\",\"key\":\"bbb\"}";
[INFO] [stderr]    |         ----^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:55:9
[INFO] [stderr]    |
[INFO] [stderr] 55 |     let mut str2 = "{xy:7,xx:\"kk\",\"key\":\"bbb\"}";
[INFO] [stderr]    |         ----^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.55s
[INFO] running `"docker" "inspect" "edb7c6ceb0d6dfe2efd86f81df8f042453e6b31810dd4f790757ffac313b1743"`
[INFO] running `"docker" "rm" "-f" "edb7c6ceb0d6dfe2efd86f81df8f042453e6b31810dd4f790757ffac313b1743"`
[INFO] [stdout] edb7c6ceb0d6dfe2efd86f81df8f042453e6b31810dd4f790757ffac313b1743