[INFO] cloning repository https://github.com/panzi/rust-json-builder
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/panzi/rust-json-builder" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpanzi%2Frust-json-builder", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpanzi%2Frust-json-builder'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 55a32321d40ad0f6ff02f1fba733afca27c31991
[INFO] checking panzi/rust-json-builder against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fpanzi%2Frust-json-builder" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/panzi/rust-json-builder on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[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-14/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 `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "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] 4a7c88b4ade2391dcc4e48696f656ee2b1b959688578f7a61e5d8cfdba7239ab
[INFO] running `Command { std: "docker" "start" "-a" "4a7c88b4ade2391dcc4e48696f656ee2b1b959688578f7a61e5d8cfdba7239ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a7c88b4ade2391dcc4e48696f656ee2b1b959688578f7a61e5d8cfdba7239ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a7c88b4ade2391dcc4e48696f656ee2b1b959688578f7a61e5d8cfdba7239ab", kill_on_drop: false }`
[INFO] [stdout] 4a7c88b4ade2391dcc4e48696f656ee2b1b959688578f7a61e5d8cfdba7239ab
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e89c75b1a5e33e0b1480fb3d35d9b05c26b36e6117a557478543c2dec968f73e
[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" "e89c75b1a5e33e0b1480fb3d35d9b05c26b36e6117a557478543c2dec968f73e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking json_builder v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/json_builder.rs:26:18
[INFO] [stdout]    |
[INFO] [stdout] 26 |     writer: &'a mut Write,
[INFO] [stdout]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/json_builder.rs:66:42
[INFO] [stdout]    |
[INFO] [stdout] 66 | pub fn escape_json(s: &str, writer: &mut Write) -> std::io::Result<()> {
[INFO] [stdout]    |                                          ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:135:26
[INFO] [stdout]     |
[INFO] [stdout] 135 |     pub fn new(writer: &mut Write) -> JSONBuilder {
[INFO] [stdout]     |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:144:33
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn new_pretty(writer: &mut Write, indent_size: usize, tab_indent: bool) -> JSONBuilder {
[INFO] [stdout]     |                                    ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:365:27
[INFO] [stdout]     |
[INFO] [stdout] 365 | impl<'a> IntoJSON for &'a IntoJSON {
[INFO] [stdout]     |                           ^^^^^^^^ help: use `dyn`: `dyn IntoJSON`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/json_builder.rs:26:18
[INFO] [stdout]    |
[INFO] [stdout] 26 |     writer: &'a mut Write,
[INFO] [stdout]    |                     ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/json_builder.rs:66:42
[INFO] [stdout]    |
[INFO] [stdout] 66 | pub fn escape_json(s: &str, writer: &mut Write) -> std::io::Result<()> {
[INFO] [stdout]    |                                          ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:135:26
[INFO] [stdout]     |
[INFO] [stdout] 135 |     pub fn new(writer: &mut Write) -> JSONBuilder {
[INFO] [stdout]     |                             ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:144:33
[INFO] [stdout]     |
[INFO] [stdout] 144 |     pub fn new_pretty(writer: &mut Write, indent_size: usize, tab_indent: bool) -> JSONBuilder {
[INFO] [stdout]     |                                    ^^^^^ help: use `dyn`: `dyn Write`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/json_builder.rs:365:27
[INFO] [stdout]     |
[INFO] [stdout] 365 | impl<'a> IntoJSON for &'a IntoJSON {
[INFO] [stdout]     |                           ^^^^^^^^ help: use `dyn`: `dyn IntoJSON`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.62s
[INFO] running `Command { std: "docker" "inspect" "e89c75b1a5e33e0b1480fb3d35d9b05c26b36e6117a557478543c2dec968f73e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e89c75b1a5e33e0b1480fb3d35d9b05c26b36e6117a557478543c2dec968f73e", kill_on_drop: false }`
[INFO] [stdout] e89c75b1a5e33e0b1480fb3d35d9b05c26b36e6117a557478543c2dec968f73e