[INFO] fetching crate const-concat 0.1.0...
[INFO] checking const-concat-0.1.0 against master#30f74ff0dc4d66debc8b50724c446f817e5f75f4 for pr-121848-1
[INFO] extracting crate const-concat 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] validating manifest of crates.io crate const-concat 0.1.0 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 const-concat 0.1.0
[INFO] finished tweaking crates.io crate const-concat 0.1.0
[INFO] tweaked toml for crates.io crate const-concat 0.1.0 written to /workspace/builds/worker-2-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] 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-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] ce8ae8240ba24ad0b36451f845d59797da9485817620b5933d9d8a2465880da0
[INFO] running `Command { std: "docker" "start" "-a" "ce8ae8240ba24ad0b36451f845d59797da9485817620b5933d9d8a2465880da0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ce8ae8240ba24ad0b36451f845d59797da9485817620b5933d9d8a2465880da0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ce8ae8240ba24ad0b36451f845d59797da9485817620b5933d9d8a2465880da0", kill_on_drop: false }`
[INFO] [stdout] ce8ae8240ba24ad0b36451f845d59797da9485817620b5933d9d8a2465880da0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] f228da1357c7900bc0610c66f97a2501556e7ce8347aa01969563a0f9e90de19
[INFO] running `Command { std: "docker" "start" "-a" "f228da1357c7900bc0610c66f97a2501556e7ce8347aa01969563a0f9e90de19", kill_on_drop: false }`
[INFO] [stderr]     Checking const-concat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:68
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                                    ^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:68
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                                    ^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_let` has been stable since 1.33.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                         ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_str_len` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:42
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                          ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `const_str_as_bytes`
[INFO] [stdout]  --> src/lib.rs:1:22
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trailing semicolon in macro used in expression position
[INFO] [stdout]   --> src/lib.rs:47:38
[INFO] [stdout]    |
[INFO] [stdout] 47 |         const_concat!($a, $($rest),*);
[INFO] [stdout]    |                                      ^
[INFO] [stdout] ...
[INFO] [stdout] 58 |         const GREETING_TRAILING_COMMA: &str = const_concat!(SALUTATION, ", ", TARGET, "!",);
[INFO] [stdout]    |                                               --------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]    = note: for more information, see issue #79813 <https://github.com/rust-lang/rust/issues/79813>
[INFO] [stdout]    = note: `#[warn(semicolon_in_expressions_from_macros)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `const_concat` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
[INFO] [stdout] help: wrap the field type in `ManuallyDrop<...>`
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: std::mem::ManuallyDrop<From>,
[INFO] [stdout]   |               +++++++++++++++++++++++    +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_let` has been stable since 1.33.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                         ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_str_len` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:42
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                          ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `const_str_as_bytes`
[INFO] [stdout]  --> src/lib.rs:1:22
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
[INFO] [stdout] help: wrap the field type in `ManuallyDrop<...>`
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: std::mem::ManuallyDrop<From>,
[INFO] [stdout]   |               +++++++++++++++++++++++    +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0557, E0635, E0740.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-concat` (lib) due to 5 previous errors; 3 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: aborting due to 4 previous errors; 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0557, E0635, E0740.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-concat` (lib test) due to 5 previous errors; 5 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "f228da1357c7900bc0610c66f97a2501556e7ce8347aa01969563a0f9e90de19", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f228da1357c7900bc0610c66f97a2501556e7ce8347aa01969563a0f9e90de19", kill_on_drop: false }`
[INFO] [stdout] f228da1357c7900bc0610c66f97a2501556e7ce8347aa01969563a0f9e90de19
[INFO] checking const-concat-0.1.0 against try#72eda894eb3548c7ba774079ce0afab42958d4ee for pr-121848-1
[INFO] extracting crate const-concat 0.1.0 into /workspace/builds/worker-2-tc2/source
[INFO] validating manifest of crates.io crate const-concat 0.1.0 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 const-concat 0.1.0
[INFO] finished tweaking crates.io crate const-concat 0.1.0
[INFO] tweaked toml for crates.io crate const-concat 0.1.0 written to /workspace/builds/worker-2-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] 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-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 7a03a7420707e1201a3ecff5e97d66d8e9db8ec1b74b21f509be5447b45e4d53
[INFO] running `Command { std: "docker" "start" "-a" "7a03a7420707e1201a3ecff5e97d66d8e9db8ec1b74b21f509be5447b45e4d53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7a03a7420707e1201a3ecff5e97d66d8e9db8ec1b74b21f509be5447b45e4d53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7a03a7420707e1201a3ecff5e97d66d8e9db8ec1b74b21f509be5447b45e4d53", kill_on_drop: false }`
[INFO] [stdout] 7a03a7420707e1201a3ecff5e97d66d8e9db8ec1b74b21f509be5447b45e4d53
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 39d258a47eadcf3d3c41df7f206d2a6f299ef436ae2f2e2c640a38d8130a9483
[INFO] running `Command { std: "docker" "start" "-a" "39d258a47eadcf3d3c41df7f206d2a6f299ef436ae2f2e2c640a38d8130a9483", kill_on_drop: false }`
[INFO] [stderr]     Checking const-concat v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |            ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:68
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                                    ^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:68
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                                    ^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: unions with `Copy` and `ManuallyDrop` fields are stable; there is no intent to stabilize more
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_let` has been stable since 1.33.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                         ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_str_len` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:42
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                          ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `const_str_as_bytes`
[INFO] [stdout]  --> src/lib.rs:1:22
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trailing semicolon in macro used in expression position
[INFO] [stdout]   --> src/lib.rs:47:38
[INFO] [stdout]    |
[INFO] [stdout] 47 |         const_concat!($a, $($rest),*);
[INFO] [stdout]    |                                      ^
[INFO] [stdout] ...
[INFO] [stdout] 58 |         const GREETING_TRAILING_COMMA: &str = const_concat!(SALUTATION, ", ", TARGET, "!",);
[INFO] [stdout]    |                                               --------------------------------------------- in this macro invocation
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]    = note: for more information, see issue #79813 <https://github.com/rust-lang/rust/issues/79813>
[INFO] [stdout]    = note: `#[warn(semicolon_in_expressions_from_macros)]` on by default
[INFO] [stdout]    = note: this warning originates in the macro `const_concat` (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
[INFO] [stdout] help: wrap the field type in `ManuallyDrop<...>`
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: std::mem::ManuallyDrop<From>,
[INFO] [stdout]   |               +++++++++++++++++++++++    +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_let` has been stable since 1.33.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:57
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                                         ^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_str_len` has been stable since 1.39.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:42
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                                          ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `const_str_as_bytes`
[INFO] [stdout]  --> src/lib.rs:1:22
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn, const_str_as_bytes, const_str_len, const_let, untagged_unions)]
[INFO] [stdout]   |                      ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: field must implement `Copy` or be wrapped in `ManuallyDrop<...>` to be used in a union
[INFO] [stdout]  --> src/lib.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: From,
[INFO] [stdout]   |         ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: union fields must not have drop side-effects, which is currently enforced via either `Copy` or `ManuallyDrop<...>`
[INFO] [stdout] help: wrap the field type in `ManuallyDrop<...>`
[INFO] [stdout]   |
[INFO] [stdout] 6 |         from: std::mem::ManuallyDrop<From>,
[INFO] [stdout]   |               +++++++++++++++++++++++    +
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors; 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0557, E0635, E0740.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-concat` (lib) due to 5 previous errors; 3 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: aborting due to 4 previous errors; 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0557, E0635, E0740.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `const-concat` (lib test) due to 5 previous errors; 5 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "39d258a47eadcf3d3c41df7f206d2a6f299ef436ae2f2e2c640a38d8130a9483", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "39d258a47eadcf3d3c41df7f206d2a6f299ef436ae2f2e2c640a38d8130a9483", kill_on_drop: false }`
[INFO] [stdout] 39d258a47eadcf3d3c41df7f206d2a6f299ef436ae2f2e2c640a38d8130a9483
