[INFO] fetching crate jstr 0.1.1...
[INFO] checking jstr-0.1.1 against try#4a23c45c7893f1416456144e3883cc48ea91722e for pr-82322
[INFO] extracting crate jstr 0.1.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate jstr 0.1.1 on toolchain 4a23c45c7893f1416456144e3883cc48ea91722e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a23c45c7893f1416456144e3883cc48ea91722e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate jstr 0.1.1
[INFO] finished tweaking crates.io crate jstr 0.1.1
[INFO] tweaked toml for crates.io crate jstr 0.1.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a23c45c7893f1416456144e3883cc48ea91722e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4a23c45c7893f1416456144e3883cc48ea91722e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4a23c45c7893f1416456144e3883cc48ea91722e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] af7005676b69d1aaea3317a30882bd16386d84a08c5a7c4c877ae17d0a5ff5b4
[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" "af7005676b69d1aaea3317a30882bd16386d84a08c5a7c4c877ae17d0a5ff5b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af7005676b69d1aaea3317a30882bd16386d84a08c5a7c4c877ae17d0a5ff5b4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af7005676b69d1aaea3317a30882bd16386d84a08c5a7c4c877ae17d0a5ff5b4", kill_on_drop: false }`
[INFO] [stdout] af7005676b69d1aaea3317a30882bd16386d84a08c5a7c4c877ae17d0a5ff5b4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4a23c45c7893f1416456144e3883cc48ea91722e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0b0ae1e5c33976312bcd4631f637f9b87c6438f658923dd10f86c49d1e6ef564
[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" "0b0ae1e5c33976312bcd4631f637f9b87c6438f658923dd10f86c49d1e6ef564", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking jstr v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused imports: `Display`, `Formatter`
[INFO] [stdout]  --> src/lib.rs:4:16
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::fmt::{Display, Formatter};
[INFO] [stdout]   |                ^^^^^^^  ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/lib.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Display`, `Formatter`
[INFO] [stdout]  --> src/lib.rs:4:16
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::fmt::{Display, Formatter};
[INFO] [stdout]   |                ^^^^^^^  ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/lib.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/lib.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 62 | / fn get_str(s: &str) -> Result<(&str, &str), Error> {
[INFO] [stdout] 63 | |     let mut esc = false;
[INFO] [stdout] 64 | |     let mut index: usize = 0;
[INFO] [stdout] 65 | |     let mut valid = false;
[INFO] [stdout] 66 | |
[INFO] [stdout] 67 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]    | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(&str, &str), Error>`
[INFO] [stdout] ...  |
[INFO] [stdout] 96 | |     }
[INFO] [stdout] 97 | | }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(&str, &str), Error>`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 99  | / fn get_num(s: &str) -> Result<(&str, &str), Error> {
[INFO] [stdout] 100 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]     | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(&str, &str), Error>`
[INFO] [stdout] 101 | |     if !(c.is_digit(10) || c == '-') {
[INFO] [stdout] 102 | |         return Err(Error::new(c, 0));
[INFO] [stdout] ...   |
[INFO] [stdout] 109 | |     return Err(Error::NoEnd);
[INFO] [stdout] 110 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(&str, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:128:11
[INFO] [stdout]     |
[INFO] [stdout] 124 | / fn get_object(s: &str) -> Result<(Object, &str), Error> {
[INFO] [stdout] 125 | |     let mut cur_s  = &s[1..];
[INFO] [stdout] 126 | |     let mut object = vec![];
[INFO] [stdout] 127 | |
[INFO] [stdout] 128 | |     while cur_s.chars().nth(0)? != '}' {
[INFO] [stdout]     | |           ^^^^^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Box<[Entry<'_>]>, &str), Error>`
[INFO] [stdout] ...   |
[INFO] [stdout] 135 | |     return Ok((Object::from(object), &cur_s[1..]));
[INFO] [stdout] 136 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Box<[Entry<'_>]>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:142:11
[INFO] [stdout]     |
[INFO] [stdout] 138 | / fn get_array(s: &str) -> Result<(Array, &str), Error> {
[INFO] [stdout] 139 | |     let mut cur_s  = &s[1..];
[INFO] [stdout] 140 | |     let mut array = vec![];
[INFO] [stdout] 141 | |
[INFO] [stdout] 142 | |     while cur_s.chars().nth(0)? != ']' {
[INFO] [stdout]     | |           ^^^^^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Box<[Value<'_>]>, &str), Error>`
[INFO] [stdout] ...   |
[INFO] [stdout] 149 | |     return Ok((Array::from(array), &cur_s[1..]));
[INFO] [stdout] 150 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Box<[Value<'_>]>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:157:13
[INFO] [stdout]     |
[INFO] [stdout] 156 | / fn get_value(s: &str) -> Result<(Value, &str), Error> {
[INFO] [stdout] 157 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]     | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Value<'_>, &str), Error>`
[INFO] [stdout] 158 | |
[INFO] [stdout] 159 | |     if c == '"' {
[INFO] [stdout] ...   |
[INFO] [stdout] 191 | |     return Err(Error::BadChar(c, 0));
[INFO] [stdout] 192 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Value<'_>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `jstr`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/lib.rs:67:13
[INFO] [stdout]    |
[INFO] [stdout] 62 | / fn get_str(s: &str) -> Result<(&str, &str), Error> {
[INFO] [stdout] 63 | |     let mut esc = false;
[INFO] [stdout] 64 | |     let mut index: usize = 0;
[INFO] [stdout] 65 | |     let mut valid = false;
[INFO] [stdout] 66 | |
[INFO] [stdout] 67 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]    | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(&str, &str), Error>`
[INFO] [stdout] ...  |
[INFO] [stdout] 96 | |     }
[INFO] [stdout] 97 | | }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(&str, &str), Error>`
[INFO] [stdout]    = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:100:13
[INFO] [stdout]     |
[INFO] [stdout] 99  | / fn get_num(s: &str) -> Result<(&str, &str), Error> {
[INFO] [stdout] 100 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]     | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(&str, &str), Error>`
[INFO] [stdout] 101 | |     if !(c.is_digit(10) || c == '-') {
[INFO] [stdout] 102 | |         return Err(Error::new(c, 0));
[INFO] [stdout] ...   |
[INFO] [stdout] 109 | |     return Err(Error::NoEnd);
[INFO] [stdout] 110 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(&str, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:128:11
[INFO] [stdout]     |
[INFO] [stdout] 124 | / fn get_object(s: &str) -> Result<(Object, &str), Error> {
[INFO] [stdout] 125 | |     let mut cur_s  = &s[1..];
[INFO] [stdout] 126 | |     let mut object = vec![];
[INFO] [stdout] 127 | |
[INFO] [stdout] 128 | |     while cur_s.chars().nth(0)? != '}' {
[INFO] [stdout]     | |           ^^^^^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Box<[Entry<'_>]>, &str), Error>`
[INFO] [stdout] ...   |
[INFO] [stdout] 135 | |     return Ok((Object::from(object), &cur_s[1..]));
[INFO] [stdout] 136 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Box<[Entry<'_>]>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:142:11
[INFO] [stdout]     |
[INFO] [stdout] 138 | / fn get_array(s: &str) -> Result<(Array, &str), Error> {
[INFO] [stdout] 139 | |     let mut cur_s  = &s[1..];
[INFO] [stdout] 140 | |     let mut array = vec![];
[INFO] [stdout] 141 | |
[INFO] [stdout] 142 | |     while cur_s.chars().nth(0)? != ']' {
[INFO] [stdout]     | |           ^^^^^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Box<[Value<'_>]>, &str), Error>`
[INFO] [stdout] ...   |
[INFO] [stdout] 149 | |     return Ok((Array::from(array), &cur_s[1..]));
[INFO] [stdout] 150 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Box<[Value<'_>]>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]    --> src/lib.rs:157:13
[INFO] [stdout]     |
[INFO] [stdout] 156 | / fn get_value(s: &str) -> Result<(Value, &str), Error> {
[INFO] [stdout] 157 | |     let c = s.chars().nth(0)?;
[INFO] [stdout]     | |             ^^^^^^^^^^^^^^^^^ cannot use the `?` operator in a function that returns `Result<(Value<'_>, &str), Error>`
[INFO] [stdout] 158 | |
[INFO] [stdout] 159 | |     if c == '"' {
[INFO] [stdout] ...   |
[INFO] [stdout] 191 | |     return Err(Error::BadChar(c, 0));
[INFO] [stdout] 192 | | }
[INFO] [stdout]     | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]     |
[INFO] [stdout]     = help: the trait `FromResidual<Option<!>>` is not implemented for `Result<(Value<'_>, &str), Error>`
[INFO] [stdout]     = note: required by `from_residual`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 5 previous errors; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "0b0ae1e5c33976312bcd4631f637f9b87c6438f658923dd10f86c49d1e6ef564", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0b0ae1e5c33976312bcd4631f637f9b87c6438f658923dd10f86c49d1e6ef564", kill_on_drop: false }`
[INFO] [stdout] 0b0ae1e5c33976312bcd4631f637f9b87c6438f658923dd10f86c49d1e6ef564