[INFO] updating cached repository https://github.com/jianantian/kvs
[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] 1d3b14dced9bb45de62eb96938c114e25aaeb78e
[INFO] checking jianantian/kvs against master#c724b67e1b474262917a5154d74e7072267593fe for pr-74315
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjianantian%2Fkvs" "/workspace/builds/worker-11/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/jianantian/kvs on toolchain c724b67e1b474262917a5154d74e7072267593fe
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/jianantian/kvs
[INFO] finished tweaking git repo https://github.com/jianantian/kvs
[INFO] tweaked toml for git repo https://github.com/jianantian/kvs written to /workspace/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/jianantian/kvs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "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] 9e3956a6a2a63f681dbee179d90828f1334dc9282fe03901fd20ef056cb773e5
[INFO] running `Command { std: "docker" "start" "-a" "9e3956a6a2a63f681dbee179d90828f1334dc9282fe03901fd20ef056cb773e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e3956a6a2a63f681dbee179d90828f1334dc9282fe03901fd20ef056cb773e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e3956a6a2a63f681dbee179d90828f1334dc9282fe03901fd20ef056cb773e5", kill_on_drop: false }`
[INFO] [stdout] 9e3956a6a2a63f681dbee179d90828f1334dc9282fe03901fd20ef056cb773e5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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@sha256:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+c724b67e1b474262917a5154d74e7072267593fe" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 408945a8e2ec133ab26eb945efbe01149ad118b29f4f3fc888994c1c15c52f0a
[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" "408945a8e2ec133ab26eb945efbe01149ad118b29f4f3fc888994c1c15c52f0a", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]    Compiling ryu v1.0.2
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]     Checking itoa v0.4.4
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking unicode-width v0.1.6
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling escargot v0.4.0
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking strsim v0.8.0
[INFO] [stderr]     Checking predicates-core v1.0.0
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking treeline v0.1.0
[INFO] [stderr]     Checking normalize-line-endings v0.2.2
[INFO] [stderr]     Checking remove_dir_all v0.5.2
[INFO] [stderr]     Checking same-file v1.0.5
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]     Checking predicates-tree v1.0.0
[INFO] [stderr]     Checking walkdir v2.2.9
[INFO] [stderr]    Compiling num-traits v0.2.9
[INFO] [stderr]     Checking c2-chacha v0.2.3
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking float-cmp v0.4.0
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking predicates v1.0.1
[INFO] [stderr]    Compiling serde_derive v1.0.102
[INFO] [stderr]     Checking serde_json v1.0.41
[INFO] [stderr]     Checking kvs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Serializer`
[INFO] [stdout]  --> src/kv.rs:3:32
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json::{Deserializer, Serializer};
[INFO] [stdout]   |                                ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `new_writer`
[INFO] [stdout]    --> src/kv.rs:245:4
[INFO] [stdout]     |
[INFO] [stdout] 245 | fn new_writer(fname: &Path, pos: u64) -> Result<BufWriterWithPos<File>, String> {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking assert_cmd v0.11.1
[INFO] [stdout] warning: unused import: `Serializer`
[INFO] [stdout]  --> src/kv.rs:3:32
[INFO] [stdout]   |
[INFO] [stdout] 3 | use serde_json::{Deserializer, Serializer};
[INFO] [stdout]   |                                ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `new_writer`
[INFO] [stdout]    --> src/kv.rs:245:4
[INFO] [stdout]     |
[INFO] [stdout] 245 | fn new_writer(fname: &Path, pos: u64) -> Result<BufWriterWithPos<File>, String> {
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 48.70s
[INFO] running `Command { std: "docker" "inspect" "408945a8e2ec133ab26eb945efbe01149ad118b29f4f3fc888994c1c15c52f0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "408945a8e2ec133ab26eb945efbe01149ad118b29f4f3fc888994c1c15c52f0a", kill_on_drop: false }`
[INFO] [stdout] 408945a8e2ec133ab26eb945efbe01149ad118b29f4f3fc888994c1c15c52f0a