[INFO] fetching crate maybe_utf8 0.2.3...
[INFO] checking maybe_utf8-0.2.3 against master#30f74ff0dc4d66debc8b50724c446f817e5f75f4 for pr-121848-1
[INFO] extracting crate maybe_utf8 0.2.3 into /workspace/builds/worker-6-tc1/source
[INFO] validating manifest of crates.io crate maybe_utf8 0.2.3 on toolchain 30f74ff0dc4d66debc8b50724c446f817e5f75f4
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate maybe_utf8 0.2.3
[INFO] finished tweaking crates.io crate maybe_utf8 0.2.3
[INFO] tweaked toml for crates.io crate maybe_utf8 0.2.3 written to /workspace/builds/worker-6-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8e44eacb425e846511bdee57720dc447970766875a5af920d1a51e06084e449f
[INFO] running `Command { std: "docker" "start" "-a" "8e44eacb425e846511bdee57720dc447970766875a5af920d1a51e06084e449f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8e44eacb425e846511bdee57720dc447970766875a5af920d1a51e06084e449f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8e44eacb425e846511bdee57720dc447970766875a5af920d1a51e06084e449f", kill_on_drop: false }`
[INFO] [stdout] 8e44eacb425e846511bdee57720dc447970766875a5af920d1a51e06084e449f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+30f74ff0dc4d66debc8b50724c446f817e5f75f4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] dc22eab8b12f2ab03b66fad2f5358c13e500b978317344fa00c86eb3a9a54273
[INFO] running `Command { std: "docker" "start" "-a" "dc22eab8b12f2ab03b66fad2f5358c13e500b978317344fa00c86eb3a9a54273", kill_on_drop: false }`
[INFO] [stderr]     Checking encoding_index_tests v0.1.4
[INFO] [stderr]     Checking maybe_utf8 v0.2.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking encoding-index-tradchinese v1.20141219.5
[INFO] [stderr]     Checking encoding-index-korean v1.20141219.5
[INFO] [stderr]     Checking encoding-index-japanese v1.20141219.5
[INFO] [stderr]     Checking encoding-index-singlebyte v1.20141219.5
[INFO] [stderr]     Checking encoding-index-simpchinese v1.20141219.5
[INFO] [stdout] error[E0432]: unresolved import `std::borrow::IntoCow`
[INFO] [stdout]   --> lib.rs:66:19
[INFO] [stdout]    |
[INFO] [stdout] 66 | use std::borrow::{IntoCow, Cow, ToOwned};
[INFO] [stdout]    |                   ^^^^^^^ no `IntoCow` in `borrow`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ToOwned` is imported redundantly
[INFO] [stdout]   --> lib.rs:66:33
[INFO] [stdout]    |
[INFO] [stdout] 66 | use std::borrow::{IntoCow, Cow, ToOwned};
[INFO] [stdout]    |                                 ^^^^^^^
[INFO] [stdout]   --> /rustc/30f74ff0dc4d66debc8b50724c446f817e5f75f4/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `ToOwned` is already defined here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Default` is imported redundantly
[INFO] [stdout]   --> lib.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | use std::default::Default;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/30f74ff0dc4d66debc8b50724c446f817e5f75f4/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `Default` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `IntoIterator` is imported redundantly
[INFO] [stdout]   --> lib.rs:69:17
[INFO] [stdout]    |
[INFO] [stdout] 69 | use std::iter::{IntoIterator, FromIterator};
[INFO] [stdout]    |                 ^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/30f74ff0dc4d66debc8b50724c446f817e5f75f4/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `IntoIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:360:17
[INFO] [stdout]     |
[INFO] [stdout] 360 |                 try!(write!(f, "b\""));
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:363:34
[INFO] [stdout]     |
[INFO] [stdout] 363 |                         b'\t' => try!(write!(f, "\\t")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:364:34
[INFO] [stdout]     |
[INFO] [stdout] 364 |                         b'\r' => try!(write!(f, "\\r")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:365:34
[INFO] [stdout]     |
[INFO] [stdout] 365 |                         b'\n' => try!(write!(f, "\\n")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:366:34
[INFO] [stdout]     |
[INFO] [stdout] 366 |                         b'\\' => try!(write!(f, "\\\\")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:367:34
[INFO] [stdout]     |
[INFO] [stdout] 367 |                         b'\'' => try!(write!(f, "\\'")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:368:34
[INFO] [stdout]     |
[INFO] [stdout] 368 |                         b'"'  => try!(write!(f, "\\\"")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:369:48
[INFO] [stdout]     |
[INFO] [stdout] 369 |                         b'\x20' ... b'\x7e' => try!(write!(f, "{}", c as char)),
[INFO] [stdout]     |                                                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `...` range patterns are deprecated
[INFO] [stdout]    --> lib.rs:369:33
[INFO] [stdout]     |
[INFO] [stdout] 369 |                         b'\x20' ... b'\x7e' => try!(write!(f, "{}", c as char)),
[INFO] [stdout]     |                                 ^^^ help: use `..=` for an inclusive range
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]     = note: `#[warn(ellipsis_inclusive_range_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:370:30
[INFO] [stdout]     |
[INFO] [stdout] 370 |                         _ => try!(write!(f, "\\x{}{}",
[INFO] [stdout]     |                              ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `core` has been stable since 1.6.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> lib.rs:63:12
[INFO] [stdout]    |
[INFO] [stdout] 63 | #![feature(core)]
[INFO] [stdout]    |            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 14 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `maybe_utf8` (lib) due to 2 previous errors; 14 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "dc22eab8b12f2ab03b66fad2f5358c13e500b978317344fa00c86eb3a9a54273", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dc22eab8b12f2ab03b66fad2f5358c13e500b978317344fa00c86eb3a9a54273", kill_on_drop: false }`
[INFO] [stdout] dc22eab8b12f2ab03b66fad2f5358c13e500b978317344fa00c86eb3a9a54273
[INFO] checking maybe_utf8-0.2.3 against try#72eda894eb3548c7ba774079ce0afab42958d4ee for pr-121848-1
[INFO] extracting crate maybe_utf8 0.2.3 into /workspace/builds/worker-6-tc2/source
[INFO] validating manifest of crates.io crate maybe_utf8 0.2.3 on toolchain 72eda894eb3548c7ba774079ce0afab42958d4ee
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate maybe_utf8 0.2.3
[INFO] finished tweaking crates.io crate maybe_utf8 0.2.3
[INFO] tweaked toml for crates.io crate maybe_utf8 0.2.3 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b2a03aa405d42d24cc17dc17097241c86ce8d74914d1fb4f8df938a7e6b4756d
[INFO] running `Command { std: "docker" "start" "-a" "b2a03aa405d42d24cc17dc17097241c86ce8d74914d1fb4f8df938a7e6b4756d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b2a03aa405d42d24cc17dc17097241c86ce8d74914d1fb4f8df938a7e6b4756d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b2a03aa405d42d24cc17dc17097241c86ce8d74914d1fb4f8df938a7e6b4756d", kill_on_drop: false }`
[INFO] [stdout] b2a03aa405d42d24cc17dc17097241c86ce8d74914d1fb4f8df938a7e6b4756d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+72eda894eb3548c7ba774079ce0afab42958d4ee" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 37dedfc88bbf5c94424373f6bca707db1b9db0dde8b97cee0c818d7f6500bb2c
[INFO] running `Command { std: "docker" "start" "-a" "37dedfc88bbf5c94424373f6bca707db1b9db0dde8b97cee0c818d7f6500bb2c", kill_on_drop: false }`
[INFO] [stderr]     Checking encoding_index_tests v0.1.4
[INFO] [stderr]     Checking maybe_utf8 v0.2.3 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking encoding-index-japanese v1.20141219.5
[INFO] [stderr]     Checking encoding-index-singlebyte v1.20141219.5
[INFO] [stderr]     Checking encoding-index-tradchinese v1.20141219.5
[INFO] [stderr]     Checking encoding-index-korean v1.20141219.5
[INFO] [stderr]     Checking encoding-index-simpchinese v1.20141219.5
[INFO] [stdout] error[E0432]: unresolved import `std::borrow::IntoCow`
[INFO] [stdout]   --> lib.rs:66:19
[INFO] [stdout]    |
[INFO] [stdout] 66 | use std::borrow::{IntoCow, Cow, ToOwned};
[INFO] [stdout]    |                   ^^^^^^^ no `IntoCow` in `borrow`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `ToOwned` is imported redundantly
[INFO] [stdout]   --> lib.rs:66:33
[INFO] [stdout]    |
[INFO] [stdout] 66 | use std::borrow::{IntoCow, Cow, ToOwned};
[INFO] [stdout]    |                                 ^^^^^^^
[INFO] [stdout]   --> /rustc/72eda894eb3548c7ba774079ce0afab42958d4ee/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `ToOwned` is already defined here
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `Default` is imported redundantly
[INFO] [stdout]   --> lib.rs:67:5
[INFO] [stdout]    |
[INFO] [stdout] 67 | use std::default::Default;
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/72eda894eb3548c7ba774079ce0afab42958d4ee/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `Default` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the item `IntoIterator` is imported redundantly
[INFO] [stdout]   --> lib.rs:69:17
[INFO] [stdout]    |
[INFO] [stdout] 69 | use std::iter::{IntoIterator, FromIterator};
[INFO] [stdout]    |                 ^^^^^^^^^^^^
[INFO] [stdout]   --> /rustc/72eda894eb3548c7ba774079ce0afab42958d4ee/library/std/src/prelude/mod.rs:105:13
[INFO] [stdout]    |
[INFO] [stdout]    = note: the item `IntoIterator` is already defined here
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:360:17
[INFO] [stdout]     |
[INFO] [stdout] 360 |                 try!(write!(f, "b\""));
[INFO] [stdout]     |                 ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:363:34
[INFO] [stdout]     |
[INFO] [stdout] 363 |                         b'\t' => try!(write!(f, "\\t")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:364:34
[INFO] [stdout]     |
[INFO] [stdout] 364 |                         b'\r' => try!(write!(f, "\\r")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:365:34
[INFO] [stdout]     |
[INFO] [stdout] 365 |                         b'\n' => try!(write!(f, "\\n")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:366:34
[INFO] [stdout]     |
[INFO] [stdout] 366 |                         b'\\' => try!(write!(f, "\\\\")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:367:34
[INFO] [stdout]     |
[INFO] [stdout] 367 |                         b'\'' => try!(write!(f, "\\'")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:368:34
[INFO] [stdout]     |
[INFO] [stdout] 368 |                         b'"'  => try!(write!(f, "\\\"")),
[INFO] [stdout]     |                                  ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:369:48
[INFO] [stdout]     |
[INFO] [stdout] 369 |                         b'\x20' ... b'\x7e' => try!(write!(f, "{}", c as char)),
[INFO] [stdout]     |                                                ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `...` range patterns are deprecated
[INFO] [stdout]    --> lib.rs:369:33
[INFO] [stdout]     |
[INFO] [stdout] 369 |                         b'\x20' ... b'\x7e' => try!(write!(f, "{}", c as char)),
[INFO] [stdout]     |                                 ^^^ help: use `..=` for an inclusive range
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021!
[INFO] [stdout]     = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]     = note: `#[warn(ellipsis_inclusive_range_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> lib.rs:370:30
[INFO] [stdout]     |
[INFO] [stdout] 370 |                         _ => try!(write!(f, "\\x{}{}",
[INFO] [stdout]     |                              ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `core` has been stable since 1.6.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> lib.rs:63:12
[INFO] [stdout]    |
[INFO] [stdout] 63 | #![feature(core)]
[INFO] [stdout]    |            ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error; 14 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `maybe_utf8` (lib) due to 2 previous errors; 14 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "37dedfc88bbf5c94424373f6bca707db1b9db0dde8b97cee0c818d7f6500bb2c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37dedfc88bbf5c94424373f6bca707db1b9db0dde8b97cee0c818d7f6500bb2c", kill_on_drop: false }`
[INFO] [stdout] 37dedfc88bbf5c94424373f6bca707db1b9db0dde8b97cee0c818d7f6500bb2c
