[INFO] fetching crate ImJson 0.0.1...
[INFO] checking ImJson-0.0.1 against try#93086cfebfccb79083c59d0d3b2052944bba643c for pr-146440-1
[INFO] extracting crate ImJson 0.0.1 into /workspace/builds/worker-7-tc2/source
[INFO] started tweaking crates.io crate ImJson 0.0.1
[INFO] removed 0 missing tests
[INFO] finished tweaking crates.io crate ImJson 0.0.1
[INFO] tweaked toml for crates.io crate ImJson 0.0.1 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate ImJson 0.0.1 on toolchain 93086cfebfccb79083c59d0d3b2052944bba643c
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+93086cfebfccb79083c59d0d3b2052944bba643c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate ImJson 0.0.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+93086cfebfccb79083c59d0d3b2052944bba643c" "fetch" "--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-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+93086cfebfccb79083c59d0d3b2052944bba643c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9e3709e2bdfdce4edba75f892998dd8cfa371d2b6b484e77d92c74af06e4b597
[INFO] running `Command { std: "docker" "start" "-a" "9e3709e2bdfdce4edba75f892998dd8cfa371d2b6b484e77d92c74af06e4b597", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9e3709e2bdfdce4edba75f892998dd8cfa371d2b6b484e77d92c74af06e4b597", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9e3709e2bdfdce4edba75f892998dd8cfa371d2b6b484e77d92c74af06e4b597", kill_on_drop: false }`
[INFO] [stdout] 9e3709e2bdfdce4edba75f892998dd8cfa371d2b6b484e77d92c74af06e4b597
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+93086cfebfccb79083c59d0d3b2052944bba643c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4d481fbe798ce30c89a3782cea18926dc5d3dde613c6151b8849eeef6fe397d3
[INFO] running `Command { std: "docker" "start" "-a" "4d481fbe798ce30c89a3782cea18926dc5d3dde613c6151b8849eeef6fe397d3", kill_on_drop: false }`
[INFO] [stderr]     Checking ImJson v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error: struct `Serializer` is never constructed
[INFO] [stdout]  --> lib/serializer.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub struct Serializer<'a> {
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `pub` struct has private fields, no public constructor, and is not otherwise reachable through the external API, so consider providing a public constructor or removing it
[INFO] [stdout]   = note: `#[deny(unused_unconstructable_pub_structs)]` (part of `#[deny(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `s` is never read
[INFO] [stdout]  --> lib/serializer.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub struct Serializer<'a> {
[INFO] [stdout]   |            ---------- field in this struct
[INFO] [stdout] 2 |     s: &'a str,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]  --> lib/deserializer.rs:7:19
[INFO] [stdout]   |
[INFO] [stdout] 7 |     pub fn new(s: &str) -> Deserializer {
[INFO] [stdout]   |                   ^^^^     ^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]   |                   |
[INFO] [stdout]   |                   the lifetime is elided here
[INFO] [stdout]   |
[INFO] [stdout]   = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]   = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]   |
[INFO] [stdout] 7 |     pub fn new(s: &str) -> Deserializer<'_> {
[INFO] [stdout]   |                                        ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ImJson` (lib test) due to 1 previous error; 2 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: struct `Serializer` is never constructed
[INFO] [stdout]  --> lib/serializer.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub struct Serializer<'a> {
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `pub` struct has private fields, no public constructor, and is not otherwise reachable through the external API, so consider providing a public constructor or removing it
[INFO] [stdout]   = note: `#[deny(unused_unconstructable_pub_structs)]` (part of `#[deny(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `s` is never read
[INFO] [stdout]  --> lib/serializer.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub struct Serializer<'a> {
[INFO] [stdout]   |            ---------- field in this struct
[INFO] [stdout] 2 |     s: &'a str,
[INFO] [stdout]   |     ^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: hiding a lifetime that's elided elsewhere is confusing
[INFO] [stdout]  --> lib/deserializer.rs:7:19
[INFO] [stdout]   |
[INFO] [stdout] 7 |     pub fn new(s: &str) -> Deserializer {
[INFO] [stdout]   |                   ^^^^     ^^^^^^^^^^^^ the same lifetime is hidden here
[INFO] [stdout]   |                   |
[INFO] [stdout]   |                   the lifetime is elided here
[INFO] [stdout]   |
[INFO] [stdout]   = help: the same lifetime is referred to in inconsistent ways, making the signature confusing
[INFO] [stdout]   = note: `#[warn(mismatched_lifetime_syntaxes)]` on by default
[INFO] [stdout] help: use `'_` for type paths
[INFO] [stdout]   |
[INFO] [stdout] 7 |     pub fn new(s: &str) -> Deserializer<'_> {
[INFO] [stdout]   |                                        ++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ImJson` (lib) due to 1 previous error; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "4d481fbe798ce30c89a3782cea18926dc5d3dde613c6151b8849eeef6fe397d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4d481fbe798ce30c89a3782cea18926dc5d3dde613c6151b8849eeef6fe397d3", kill_on_drop: false }`
[INFO] [stdout] 4d481fbe798ce30c89a3782cea18926dc5d3dde613c6151b8849eeef6fe397d3