[INFO] updating cached repository https://github.com/panzi/rust-json-builder
[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] 55a32321d40ad0f6ff02f1fba733afca27c31991
[INFO] checking panzi/rust-json-builder against master#45d050cde277b22a755847338f2acc2c7b834141 for pr-71393
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpanzi%2Frust-json-builder" "/workspace/builds/worker-1/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/panzi/rust-json-builder on toolchain 45d050cde277b22a755847338f2acc2c7b834141
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/panzi/rust-json-builder
[INFO] finished tweaking git repo https://github.com/panzi/rust-json-builder
[INFO] tweaked toml for git repo https://github.com/panzi/rust-json-builder written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/panzi/rust-json-builder already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+45d050cde277b22a755847338f2acc2c7b834141" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+45d050cde277b22a755847338f2acc2c7b834141" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] ff805caa4bde1f6c01e55ad449e47bd9e9785fa50823eb153b42c06b33635db4
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "ff805caa4bde1f6c01e55ad449e47bd9e9785fa50823eb153b42c06b33635db4"`
[INFO] [stderr]     Checking json_builder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/json_builder.rs:26:18
[INFO] [stderr]    |
[INFO] [stderr] 26 |     writer: &'a mut Write,
[INFO] [stderr]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/json_builder.rs:66:42
[INFO] [stderr]    |
[INFO] [stderr] 66 | pub fn escape_json(s: &str, writer: &mut Write) -> std::io::Result<()> {
[INFO] [stderr]    |                                          ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:135:26
[INFO] [stderr]     |
[INFO] [stderr] 135 |     pub fn new(writer: &mut Write) -> JSONBuilder {
[INFO] [stderr]     |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:144:33
[INFO] [stderr]     |
[INFO] [stderr] 144 |     pub fn new_pretty(writer: &mut Write, indent_size: usize, tab_indent: bool) -> JSONBuilder {
[INFO] [stderr]     |                                    ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:365:27
[INFO] [stderr]     |
[INFO] [stderr] 365 | impl<'a> IntoJSON for &'a IntoJSON {
[INFO] [stderr]     |                           ^^^^^^^^ help: use `dyn`: `dyn IntoJSON`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/json_builder.rs:26:18
[INFO] [stderr]    |
[INFO] [stderr] 26 |     writer: &'a mut Write,
[INFO] [stderr]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]   --> src/json_builder.rs:66:42
[INFO] [stderr]    |
[INFO] [stderr] 66 | pub fn escape_json(s: &str, writer: &mut Write) -> std::io::Result<()> {
[INFO] [stderr]    |                                          ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:135:26
[INFO] [stderr]     |
[INFO] [stderr] 135 |     pub fn new(writer: &mut Write) -> JSONBuilder {
[INFO] [stderr]     |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:144:33
[INFO] [stderr]     |
[INFO] [stderr] 144 |     pub fn new_pretty(writer: &mut Write, indent_size: usize, tab_indent: bool) -> JSONBuilder {
[INFO] [stderr]     |                                    ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stderr] 
[INFO] [stderr] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stderr]    --> src/json_builder.rs:365:27
[INFO] [stderr]     |
[INFO] [stderr] 365 | impl<'a> IntoJSON for &'a IntoJSON {
[INFO] [stderr]     |                           ^^^^^^^^ help: use `dyn`: `dyn IntoJSON`
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.33s
[INFO] running `"docker" "inspect" "ff805caa4bde1f6c01e55ad449e47bd9e9785fa50823eb153b42c06b33635db4"`
[INFO] running `"docker" "rm" "-f" "ff805caa4bde1f6c01e55ad449e47bd9e9785fa50823eb153b42c06b33635db4"`
[INFO] [stdout] ff805caa4bde1f6c01e55ad449e47bd9e9785fa50823eb153b42c06b33635db4