[INFO] crate maybe_utf8 0.2.3 is already in cache
[INFO] testing maybe_utf8-0.2.3 against beta-2020-07-24 for beta-1.46-1
[INFO] extracting crate maybe_utf8 0.2.3 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate maybe_utf8 0.2.3 on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", 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-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e9ed5c00334f72329b0f70a29d13afa52b692a5f422b4ac97516c1c9917b1b4a
[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" "e9ed5c00334f72329b0f70a29d13afa52b692a5f422b4ac97516c1c9917b1b4a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e9ed5c00334f72329b0f70a29d13afa52b692a5f422b4ac97516c1c9917b1b4a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e9ed5c00334f72329b0f70a29d13afa52b692a5f422b4ac97516c1c9917b1b4a", kill_on_drop: false }`
[INFO] [stdout] e9ed5c00334f72329b0f70a29d13afa52b692a5f422b4ac97516c1c9917b1b4a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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=warn" "-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@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 949c8e8d433b526805cf2695eb7840c64ad273c84aa3dc1ac16b69c912e1c2f0
[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" "949c8e8d433b526805cf2695eb7840c64ad273c84aa3dc1ac16b69c912e1c2f0", kill_on_drop: false }`
[INFO] [stderr]    Compiling maybe_utf8 v0.2.3 (/opt/rustwide/workdir)
[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] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> lib.rs:63:1
[INFO] [stdout]    |
[INFO] [stdout] 63 | #![feature(core)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated item '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 item '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 item '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 item '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 item '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 item '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 item '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 item '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: use of deprecated item '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: `...` 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]     = note: `#[warn(ellipsis_inclusive_range_patterns)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors; 10 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0432, E0554.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0432`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `maybe_utf8`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "949c8e8d433b526805cf2695eb7840c64ad273c84aa3dc1ac16b69c912e1c2f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "949c8e8d433b526805cf2695eb7840c64ad273c84aa3dc1ac16b69c912e1c2f0", kill_on_drop: false }`
[INFO] [stdout] 949c8e8d433b526805cf2695eb7840c64ad273c84aa3dc1ac16b69c912e1c2f0